Portable defect mitigators for electrochromic windows

ABSTRACT

Portable apparatus for identifying and mitigating defects in electronic devices disposed on substrates or windows are disclosed herein. Such defects can be visually perceived by the end user. The substrates or windows may include flat panel displays, photovoltaic windows, electrochromic devices, and the like, particularly electrochromic windows.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a divisional application of U.S. patent application Ser. No.13/859,623 filed on Apr. 9, 2013, titled “PORTABLE DEFECT MITIGATORS FORELECTROCHROMIC WINDOWS,” which is a continuation-in-part application ofU.S. patent application Ser. No. 13/610,612, filed on Sep. 11, 2012 (nowU.S. Pat. No. 9,507,232), titled “PORTABLE DEFECT MITIGATOR FORELECTROCHROMIC WINDOWS,” which claims priority to U.S. ProvisionalPatent Application No. 61/534,712, filed on Sep. 14, 2011 and titled“PORTABLE DEFECT MITIGATOR FOR ELECTROCHROMIC WINDOWS,” and claimspriority to U.S. Provisional Patent Application No. 61/614,668, filed onMar. 23, 2012 and titled “PORTABLE DEFECT MITIGATOR FOR ELECTROCHROMICWINDOWS,” all of these applications are hereby incorporated by referencein their entirety and for all purposes.

FIELD

The present disclosure concerns apparatus, systems, and methods formitigating defects in electronic devices on substrates, e.g., where suchdefects can be visually perceived by the end user, such as flat paneldisplays, photovoltaic windows, electrochromic devices, and the like,particularly electrochromic windows.

BACKGROUND

Electrochromism is a phenomenon in which a material exhibits areversible electrochemically-mediated change in an optical property whenplaced in a different electronic state, typically by being subjected toa voltage change. The optical property is typically one or more ofcolor, transmittance, absorbance, and reflectance. While electrochromismwas discovered in the 1960s, electrochromic devices still unfortunatelysuffer various problems and have not begun to realize their fullcommercial potential.

Electrochromic materials may be incorporated into, for example, windowsand mirrors. The color, transmittance, absorbance, and/or reflectance ofsuch windows and mirrors may be changed by inducing a change in theelectrochromic material. However, advancements in electrochromictechnology, apparatus, and related methods of making and/or using them,are needed because conventional electrochromic windows suffer from, forexample, high defectivity and low versatility.

Electrochromic windows are made by forming an electrochromic device on apane of transparent material. During production, the electrochromicdevice on the pane is scrutinized for any defects that would causevisual distortions or anomalies to the end user of the window. Thesedefects are then mitigated. Mitigation may include isolating short typedefects using probes and then “zapping” the short defect by applying alocalized electric arc to overload and destroy the short conductionpath. Other methods of mitigation include, for example, identifyingvisual defects and then circumscribing each defect with a laser toelectronically isolate the defect and thereby lower or eliminate thevisual effect the defect would create when the window is in a coloredstate. Similar mitigation efforts are made for other electronic deviceson substrates where such defects can be visually perceived by the enduser, such as flat panel displays. The electronic device may be analyzedfor defects on one machine and then the defects mitigated on anothermachine in a production facility setting. Such defect detection andmitigation apparatus for flat panel displays are commercially available,for example, under the trade names of ArrayChecker™ and ArraySaver™which are made by Orbotech Inc. of Billerica, Mass.

SUMMARY

Systems, methods, an apparatus for identifying and mitigating defects inelectronic devices on substrates, which may be included in flat paneldisplays, photovoltaic windows, electrochromic windows, and the like. Insome cases, the apparatus may be a portable defect mitigator that can beeasily transported to identify and mitigate a defect in the electronicdevice located in the field (e.g., an electrochromic window installed ina building). The portable defect mitigator may be a hand-held operateddesign that can be easily maneuvered and affixed to the surface of thewindow during the procedure.

In the field, a window may be subjected to forces (e.g., wind gusts)that can bend or otherwise deform the window. Certain embodimentsinclude a dynamic autofocus system for automatically focusing a laserduring mitigation of a defect in an electronic device of a deformingwindow. The dynamic autofocus system has a focal lens for focusing thecollimated light from a laser mitigating the defect. The dynamicautofocus system also has a detector mechanism (e.g., triangulationsensor) for measuring a separation distance to the surface of theelectronic device. The detector mechanism takes this measurement at oneor more sample times. The dynamic autofocus system also has a lenspositioning mechanism for moving the lens to about a focal length fromthe surface of the electronic device based on the separation distancemeasured at the sample time. The dynamic autofocus system also has aprocessor that can send a signal to the lens positioning mechanism tomove the focal lens. In one case, the detector mechanism also measures arate of change of the separation distance at the sample time. Theprocessor predicts the separation distance at a future time based on theseparation distance and its rate of change measured at the sample time.The lens positioning mechanism moves the lens to about the focal lengthbased on the predicted separation distance at the future time determinedfrom the measured separation distance and rate of change at the sampletime.

In one aspect, the portable defect mitigator may include a vacuumengagement system for affixing the mitigator to a window surface. Thevacuum engagement system includes a plurality of isolated recesses and agroove around each of the recesses. The system also includes O-rings,each O-ring is configured to fit within one of the grooves. Each of therecesses is vacuum sealed with the O-ring to form a vacuum chamber withthe window surface. The vacuum engagement system may a set of valves.Each valve is configured to control vacuum in one of the vacuumchambers. The valves may be independently controlled.

In some embodiments, a portable defect mitigator includes a firstmechanism configured to detect the defect, a second mechanism configuredto mitigate the defect, and a dichroic mirror for receiving collimatedillumination from the first mechanism and the second mechanism. Theportable defect mitigator also includes a reflective mirror forreceiving collimated illumination along a coaxial path from the dichroicmirror and a focal lens receiving collimated illumination reflected fromthe mirror and focusing the illumination to the electronic device toimage and mitigate the defect. In some cases, the portable defectmitigator may include a pivoting mechanism for pivoting the mirror andfocal lens about a pivot point to focus the illumination at an angle toa plane at a surface of the electronic device. For example, the focallens can focus the illumination to a focal point at a corner of aninsulated glass unit. As another example, the focal lens can focus theillumination to a focal point under a spacer of an insulated glass unit.

One embodiment is a method of mitigating a defect in an electronicdevice on a window using a portable defect mitigator. The methodincludes mounting the portable defect mitigator to a surface of thewindow. The method also includes focusing a laser on the surface of theelectronic device and identifying one or more defects in a field ofview. The method also includes mitigating a selected defect using alaser based on a selected scribe pattern.

In embodiments, the portable defect mitigator may include one or moresubsystems with a variety of functionalities. One subsystem is an X-Ystage for increasing the field of view of the mitigating laser and theimaging device. Another subsystem is a Z-stage for moving the focalpoint of the laser and/or imaging device. Another subsystem is a tethersystem for tethering the portable defect mitigator for added safety.Another subsystem is a vacuum engagement system for affixing theportable defect mitigator to the surface of the window. Anothersubsystem is a dynamic autofocus system. Another subsystem includesimaging and mitigation systems which share a common axis from a dichroicmirror through the focal lens and onto the window surface. Anothersubsystem is a pivot system for pivoting the optics in a portable defectmitigator mounted to the window in order to image and mitigate defectsat the corners or underneath a spacer of an IGU. Another subsystem is alight tight hand-held chassis and/or a case-like structure separate fromthe chassis. Another subsystem is a tracking stylus for manuallyinputting defect locations. Another subsystem is a beam blocker.

These and other features and embodiments will be described in moredetail below with reference to the drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A and 1B depict the structure and function of electrochromicdevices.

FIG. 2 depicts a particle defect in an electrochromic device.

FIGS. 3A-3C depict aspects of formation of a pop-off defect.

FIG. 4 depicts aspects of a dark field illumination technique.

FIG. 5A depicts a perspective of an apparatus for identifying andremediating a visual defect.

FIG. 5B depicts a rail or track system for apparatus as describedherein.

FIG. 5C depicts a coaxial optical path for laser and detection optics.

FIG. 5D depicts a pre-firing alignment process.

FIGS. 6 and 7 depict various aspects of apparatus for identifying andremediating a visual defect.

FIGS. 8A-8C depict aspects of a process flow.

FIG. 9 is a schematic diagram of a dynamic autofocus system in aportable defect mitigator, according to embodiments.

FIG. 10 is a schematic diagram of a triangulation sensor of a dynamicautofocus system, according to embodiments.

FIG. 11A is a schematic diagram of an optical system in a compactarrangement having a mirror at a nominal position, according toembodiments.

FIG. 11B is a schematic diagram of the optical system of FIG. 11A withthe mirror tilted upward.

FIG. 12 is a schematic diagram of an optical system in a compactarrangement, according to embodiments.

FIGS. 13A-H are isometric line drawings of a portable defect mitigator,according to embodiments.

FIG. 14 is a flowchart of a method of using a portable defect mitigator,according to embodiments.

DETAILED DESCRIPTION

Electrochromic Devices

FIGS. 1A and 1B are schematic cross-sections of an electrochromicdevice, 100, showing a common structural motif for such devices, andfurther, the function of such devices is summarized below.Electrochromic device 100 includes a substrate 102, a conductive layer(CL) 104, an electrochromic layer (EC) 106, an ion conducting(electrically resistive) layer (IC) 108, a counter electrode layer (CE)110, and another conductive layer (CL) 112. Elements 104, 106, 108, 110,and 112 are collectively referred to as an electrochromic stack, 114. Avoltage source, 116, operable to apply an electric potential acrosselectrochromic stack 112 effects the transition of the electrochromicdevice from, e.g., a bleached state (refer to FIG. 1A) to a coloredstate (refer to FIG. 1B). The order of layers may be reversed withrespect to the substrate. That is, the layers may be in the followingorder: substrate, conductive layer, counter electrode layer, ionconducting layer, electrochromic material layer, and conductive layer.The conductive layers commonly comprise transparent conductivematerials, such as metal oxides, alloy oxides, and doped versionsthereof, and are commonly referred to as “TCO” layers because they aremade from transparent conducting oxides. Device 100 is meant forillustrative purposes, in order to understand the context of embodimentsdescribed herein. Methods and apparatus described herein are used toidentify and mitigate defects in electrochromic devices, regardless ofthe structural motif of the electrochromic device, so long as there is astacked device structure that functions similarly to device 100, thatis, devices that can have visual defects that can be mitigated asdescribed herein.

During normal operation, electrochromic devices such as 100 reversiblycycle between a bleached state and a colored state. As depicted in FIG.1A, in the bleached state, a potential is applied across the electrodes(transparent conductor layers 104 and 112) of electrochromic stack 114such that available ions (e.g. lithium ions) in the stack that wouldotherwise cause electrochromic material 106 to be in the colored statereside primarily in the counter electrode 110, and thus electrochromiclayer 106 is in a bleached state. In certain electrochromic devices,when loaded with the available ions, counter electrode layer 110 is alsoin a bleached state (thus it can be thought of as an ion storage area ofthe device).

Referring to FIG. 1B, when the potential on the electrochromic stack isreversed, the ions are transported across ion conducting layer 108 toelectrochromic layer 106 and cause the material to enter the coloredstate. In certain electrochromic devices, the depletion of ions from thecounter electrode material causes it to color also (as depicted, thus inthis example counter electrode layer 110 is a lithium storage area whenthe device is bleached, and also functions to color the device when theions leave layer 110). Thus, there is a synergistic effect where thetransition to colored states for both layers 106 and 110 are additivetoward reducing the amount of light transmitted through the stack. Whenthe voltage is no longer applied to device 100, ions travel fromelectrochromic layer 106, through the ion conducting layer 108, and backinto counter electrode layer 110.

Electrochromic devices such as described in relation to FIGS. 1A and 1Bare used to fabricate, for example, electrochromic windows. For example,substrate 102 may be architectural glass upon which electrochromicdevices are fabricated. Architectural glass is glass that is used as abuilding material. Architectural glass is typically used in commercialbuildings, but may also be used in residential buildings, and typically,though not necessarily, separates an indoor environment from an outdoorenvironment. In certain embodiments, architectural glass is at least 20inches by 20 inches, and can be much larger, e.g., as large as about 72inches by 120 inches.

As larger and larger substrates are used for electrochromic windows itis desirable to minimize defects in the electrochromic device, becauseotherwise the performance and visual quality of the electrochromicwindows will suffer. Even if defects are minimized, there will be somedefects in the final product that must be mitigated. Understanding theneeds addressed by embodiments described herein requires a betterunderstanding of defectivity in electrochromic windows.

Defectivity in Electrochromic Windows

As used herein, the term “defect” refers to a defective point or regionof an electrochromic device. Defects may be caused by electrical shortsor by pinholes. Further, defects may be characterized as visible ornon-visible. In general, a defect in an electrochromic device, andsometimes an area around the defect, does not change optical state(e.g., color) in response to an applied potential that is sufficient tocause non-defective regions of the electrochromic device to color orotherwise change optical state. Often a defect will be manifest asvisually discernible anomalies in the electrochromic window or otherdevice. Such defects are referred to herein as “visible” defects. Otherdefects are so small that they are not visually noticeable to theobserver in normal use (e.g., such defects do not produce a noticeablelight point or “pinhole” when the device is in the colored state duringdaytime).

A short is a localized electronically conductive pathway spanning theion conducting layer (e.g., an electronically conductive pathway betweenthe two TCO layers). Typically, a defect causing a visible short willhave a physical dimension of about 3 micrometers, sometimes less, whichis a relatively small defect from a visual perspective. However, theserelatively small defects result in a visual anomaly, the halo, in thecolored electrochromic window that are, for example, about 1 centimeterin diameter, sometimes larger. Halos can be reduced significantly byisolating the defect, for example by circumscribing the defect via alaser scribe or by ablating the material directly without circumscribingit. For example, a circular, oval, triangular, rectangular, or othershaped perimeter is ablated around the shorting defect thus electricallyisolating it from the rest of the functioning device. Thecircumscription may be only tens, a hundred, or up to a few hundredmicrometers in diameter. By circumscribing, and thus electricallyisolating the defect, the visible short will resemble only a small pointof light to the naked eye when the window is colored and there issufficient light on the other side of the window. When ablated directly,without circumscription, there remains no EC device material in the areawhere the electrical short defect once resided. Rather, there is a holethrough the device and at the base of the hole is, for example, thefloat glass or the diffusion barrier or the lower transparent electrodematerial, or a mixture thereof. Since these materials are alltransparent, light may pass through the base of the hole in the device.Depending on the diameter of a circumscribed defect, and the width ofthe laser beam, circumscribed pinholes may also have little or noelectrochromic material remaining within the circumscription (as thecircumscription is typically, though not necessarily, made as small aspossible). Such mitigated short defects manifest as pin points of lightagainst the colored device, thus these points of light are commonlyreferred to as “pinholes.” Isolation of an electrical short bycircumscribing or direct ablation would be an example of a man-madepinhole, one purposely formed to convert a halo into a much smallervisual defect. However, pinholes may also arise as a natural result ofdefects in the optical device.

A pinhole is a region where one or more layers of the electrochromicdevice are missing or damaged so that electrochromism is not exhibited.Pinholes are not electrical shorts, and, as described above, they may bethe result of mitigating an electrical short in the device. A pinholemay have a defect dimension of between about 25 micrometers and about300 micrometers, typically between about 50 micrometers and about 150micrometers, thus it is much harder to discern visually than a halo.Typically, in order to reduce the visible perception of pinholesresulting from mitigation of halos, one will limit the size of apurposely-created pinhole to about 100 micrometers or less.

Particle Location Worst Case Failure Effect on substrate pops offleaving pinhole pinhole on TEC pops off allowing ITO- visible short TECshort voltage drop on EC leakage across IC visible short voltage drop onIC pops off leaving pinhole pinhole on CE pops off leaving pinholepinhole

In some cases, an electrical short is created by a conductive particlelodging in and/or across the ion conducting layer, thereby causing anelectronic path between the counter electrode layer and theelectrochromic layer or the TCO associated with either one of them. Adefect may also be caused by a particle on the substrate on which theelectrochromic stack is fabricated. When such a particle causes layerdelamination due to stresses imparted by the particle, this is sometimescalled “pop-off” In other instances, the layers do not adhere to thesubstrate properly and delaminate, interrupting the flow of ions and/orelectrical current within the device. These types of defects aredescribed in more detail below in relation to FIGS. 2 and 3A-3C. Adelamination or pop-off defect can lead to a short if it occurs before aTCO or associated EC or CE is deposited. In such cases, the subsequentlydeposited TCO or EC/CE layer will directly contact an underlying TCO orCE/EC layer providing direct electronic conductive pathway. A fewexamples of defect sources are presented in the table below. The tablebelow is intended to provide examples of mechanisms that lead to thedifferent types of visible and non-visible defects. Additional factorsexist which may influence how the EC window responds to a defect withinthe stack.

As noted above, in the case of a visible short the defect will appear asa light central region (when the device is in the colored state) with adiffuse boundary such that the device gradually darkens with distancefrom the center of the short. If there are a significant number ofelectrical shorts (visible or non-visible) concentrated in an area of anelectrochromic device, they may collectively impact a broad region ofthe device whereby the device cannot switch in such region. This isbecause the potential difference between the EC and CE layers in suchregions cannot attain a threshold level required to drive ions acrossthe ion conductive layer. It should be understood that leakage currentmay result from sources other than short-type defects. Such othersources include broad-based leakage across the ion conducting layer andedge defects such as roll off defects as described elsewhere herein andscribe line defects. The emphasis here is on leakage caused only bypoints of electrical shorting across the ion conducting layer in theinterior regions of the electrochromic device. These shorts causevisible defects that must be minimized and/or mitigated for theelectrochromic pane to be acceptable for use in an electrochromicwindow. Conventionally, the visual defects are identified and mitigatedprior to assembly of the pane into an insulated glass unit (IGU).Methods described herein allow identification and mitigation after thepane is fabricated into an IGU and also after installed in a buildingor, for example, after the pane is installed in an automobile.

Since an IGU may include more than two glass panes assembled into a unit(e.g. a triple pane unit), and for electrochromic windows specificallymay include electrical leads for connecting the electrochromic glass toa voltage source, switches and the like, the term “window unit” is usedto convey a more simple sub-assembly. That is, for the purposes of thisinvention, an IGU may include more components than a window unit. Themost basic assembly of a window unit is two substrates (panes orglazings) with a sealing separator in between and registered with thetwo substrates.

FIG. 2 is a schematic cross-section of an electrochromic device, 200,with a particle, 205, in the ion conducting layer causing a localizeddefect in the device. In this example, electrochromic device 200includes the same layers as described in relation to FIGS. 1A and 1B.Voltage source 116 is configured to apply a potential to electrochromicstack 114 as described above, through suitable connections (e.g., busbars) to conductive layers 104 and 112.

In this example, ion conducting layer 108 includes a conductiveparticle, 205, or other artifact causing a defect. Conductive particle205 results in a short between electrochromic layer 106 and counterelectrode layer 110. In this example, particle 205 spans the thicknessof the IC layer 108. Particle 205 physically impedes the flow of ionsbetween electrochromic layer 106 and counter electrode layer 110, andalso, due to its electrical conductivity, allows electrons to passlocally between the layers, resulting in a transparent region 210 inelectrochromic layer 106 and a transparent region 220 in counterelectrode layer 110. Transparent region 210 exists when the remainder oflayers 110 and 106 are in the colored state. That is, if electrochromicdevice 200 is in the colored state, conductive particle 205 rendersregions 210 and 220 of the electrochromic device unable to enter intothe colored state. Sometimes such visible defect regions are referred toas “constellations” or “halos” because they appear as a series of brightspots (or stars) against a dark background (the remainder of the devicebeing in the colored state). Humans will naturally direct theirattention to the halos and often find them distracting or unattractive.Embodiments described herein identify and mitigate such visible defects.Pinhole defects may or may not be deemed worthy of repair, as they canbe nearly indiscernible to the naked eye by most observers.

It should be noted that defect mitigators described herein may haveoptical detection components that allow detection of defects notdiscernible to the human eye. Moreover, the mitigation componentsdescribed herein can repair such defects. Embodiments described hereinare thus not limited to portable defect mitigators that detect andrepair defects visually discernible to the human eye; however, visuallydiscernible defects are of most concern from an end user perspective.Non-visually discernible defects can lead to poor device performance inthe aggregate due to their associated leakage current, and thus may alsobe mitigated using apparatus and methods as described herein.

As mentioned above, visible short defects can also be caused byparticles popping off, e.g. during or after fabrication of theelectrochromic device, thereby creating damaged areas in theelectrochromic stack, through one or more layers of the stack. Pop-offdefects are described in more detail below.

FIG. 3A is a schematic cross-section of an electrochromic device, 300,with a particle 305 or other debris on conductive layer 104 prior todepositing the remainder of the electrochromic stack. Electrochromicdevice 300 includes the same components as electrochromic device 100.Particle 305 causes the layers in the electrochromic stack 114 to bulgein the region of particle 305, due to conformal layers 106-110 beingdeposited sequentially over particle 305 as depicted (in this example,conductive layer 112 has not yet been deposited). While not wishing tobe bound by a particular theory, it is believed that layering over suchparticles, given the relatively thin nature of the layers, can causestress in the area where the bulges are formed. More particularly, ineach layer, around the perimeter of the bulged region, there can bedefects in the layer, e.g. in the lattice arrangement or on a moremacroscopic level, cracks or voids. One consequence of these defectswould be, for example, an electrical short between electrochromic layer106 and counter electrode layer 110 and/or loss of ion conductivity inlayer 108. These defects are not depicted in FIG. 3A, however.

Referring to FIG. 3B, another consequence of defects caused by particle305 is called a “pop-off.” In this example, prior to deposition ofconductive layer 112, a portion above the conductive layer 104 in theregion of particle 305 breaks loose, carrying with it portions ofelectrochromic layer 106, ion conducting layer 108, and counterelectrode layer 110. The “pop-off” is piece 310, which includes particle305, a portion of electrochromic layer 106, as well as ion conductinglayer 108 and counter electrode layer 110. The result is an exposed areaof conductive layer 104 at the bottom of the trench left when piece 310popped out of the layered stack of materials. Referring to FIG. 3C,after pop-off and once conductive layer 112 is deposited, an electricalshort is formed where conductive layer 112 comes in contact withconductive layer 104. This electrical short would leave a transparentregion in electrochromic device 300 when it is in the colored state,similar in appearance to the visual defect created by the shortdescribed above in relation to FIG. 2.

Pop-off defects due to particles or debris on the substrate, ionconducting layer, and on the counter electrode layer may also causepinhole defects. Also, if a contaminate particle is large enough anddoes not cause a pop-off, it might be visible when the electrochromicdevice is in the bleached state.

The description above, as described in relation to FIGS. 1A, 1B, 2, and3A-C, presumes that there is a distinct ion conducting (electronicallyresistive) layer sandwiched between an electrochromic layer and acounter electrode layer in electrochromic devices. The description isonly meant to be illustrative of how a particle can create a shortrelated defect. That is, there are electrochromic devices where adistinct electronically resistive and ion conducting layer does notexist, but rather an interfacial region that serves as an ion conductivelayer exists at the interface of the electrochromic and counterelectrode layers. Electrochromic devices having this architecture aredescribed in U.S. patent application Ser. No. 12/772,055 filed Apr. 30,2010, Ser. No. 12/772,075 filed Apr. 30, 2010, Ser. No. 12/814,277 filedJun. 11, 2010, Ser. No. 12/814,279 filed Jun. 11, 2010 and Ser. No.13/166,537 filed Jun. 22, 2011, each entitled, “Electrochromic Devices,”each having inventors Wang et al., and each hereby incorporated byreference in their entirety. Thus particles can cause shorting defectsin these devices as well, e.g., where the particle exists at and/orcrosses the interface between the electrochromic and counter electrodelayers and/or creates pop-off type defects as described. Such devicesare also susceptible to other defect types described herein, despite nothaving a distinct IC layer as in conventional devices.

Thus, there are three types of defects are of primary concern withregard to electrochromic windows: (1) visible pinholes, (2) visibleshorts, and (3) non-visible shorts. A visible pinhole will have a defectdimension of at least about 100 μm, and manifest as a very small pointof light when the window is colored, sometimes barely discernible to thenaked eye, but visible upon close scrutiny. Typically, though notnecessarily, a visible short will have defect dimension of at leastabout 3 micrometers resulting in a region, e.g. of about 1 cm indiameter, often referred to as a “halo,” where the electrochromic effectis perceptibly diminished. These halo regions can be reducedsignificantly by isolating the defect causing the visible short so thatto the naked eye the visible short will resemble only a visible pinhole.Non-visible shorts can affect switching performance of theelectrochromic device, by contributing to the overall leakage current ofthe device, but do not create discernible points of light or halos whenthe window is in a colored state.

Embodiments described herein include apparatus and methods where visibledefects are identified and mitigated. In certain embodiments, thevisible defect is due to a visible short, i.e., a visible defect thatproduces a halo is identified and mitigated. Visible short defects thatproduce halos are described in more detail below.

Visible shorts produce a halo when the device is darkened. A halo is aregion in the device where an electrical short across the electrochromicstack causes an area around the short to drain current into the shortand therefore the area surrounding the short is not darkened. Asmentioned, these regions can be up to about 1 cm in diameter, and thuspresent a problem by making the electrochromic window, when colored,unattractive to the observer. This frustrates the purpose of havingwindows that can operate in a colored mode.

Conventionally visible short defects are mitigated after fabrication ofthe electrochromic device, but while still in the production facility,for example, prior to installation in an IGU. For example, individualelectrochromic panes are characterized by first applying temporary busbars and then coloring the electrochromic device. Visual defects such ashalos are identified and then mitigated, for example, lasercircumscribed to isolate them and remove the halo effect, which leavessmaller, less discernible, pinhole defects. As described above,conventionally, at least two, large, dedicated apparatus, are used tocarry out identification and mitigation of visual defects. However,defects can form in the electrochromic devices after the devices leavethe production facility due to, for example, the inherent stresses inelectrochromic devices (e.g. see above) and/or stresses applied to thewindows during normal use such as installation, pressure differentialbetween interior and exterior space, impacts that do not break thewindow pane and the like. Conventionally, for electrochromic windowsalready installed in a vehicle or building, mitigating such defectswould not be done, rather the unit would be replaced in the field. Thiscan be very expensive. As well, mitigating defects in existingelectrochromic windows in the field would greatly extend the usablelifetime of the windows. Thus embodiments described herein includeportable apparatus for identifying and mitigating visual defects.

Portable Defect Mitigators

Embodiments described herein include apparatus and methods foridentifying and mitigating visual defects in electrochromic or otherdevices where a visually discernible defect can be identified andmitigated as described herein. Such apparatus may be referred to hereinas “defect mitigators,” though their function includes components forboth identifying and mitigating visual defects. In certain embodiments,apparatus for identifying and mitigating visual defects are portable.“Portable” in this context means that such apparatus can readily bemoved and/or transported in order to identify and mitigate a visualdefect in an electrochromic window or other device in the field, forexample, an electrochromic window that is installed in a building, anautomobile, and the like. That is, the apparatus can be, for example,carried by hand or otherwise manipulated by one or more users in orderto position the apparatus proximate to an electrochromic window andcarry out the functions of identifying a visual defect and mitigatingthe visual defect using the apparatus.

Portable apparatus for identifying and mitigating visual defects inelectronic devices, such as those used in flat panel displays,photovoltaic windows and electrochromic windows, provide significantadvantages over large, dedicated apparatus in a production facilitysetting. In particular, the portability of the apparatus allows for itsuse in the field, including on installed devices. Due to inherentstresses in electronic devices such as electrochromic windows and/orstresses applied to the devices, defects can form after the devicesleave the production facility. This is a problem, especially for devicesthat are installed in a permanent fashion, such as an electrochromicwindow installed in a vehicle or building. Typically, when such visualdefects arise in an electrochromic window, the window must be replaced.This can be costly, because electrochromic windows have associatedwiring and related hardware. For example, recently, replacing fourdefective electrochromic windows in a prominent downtown London buildingwas estimated to cost nearly €1 million. As well, avoiding replacementby mitigating defects in existing electrochromic windows in the fieldwould greatly extend their usable lifetime.

In certain embodiments, a portable apparatus will attach to the walland/or window frame in order to carry out identification and mitigationof visual defects in an electrochromic window. In some embodiments, theportable apparatus will attach to the electrochromic window glass inorder to identify and mitigate visual defects. This mode of attachmentmay be on a pane bearing an electrochromic device or a pane of an IGUthat does not have an electrochromic device on it, e.g., defects areidentified and mitigated on one pane, through another pane not having anelectrochromic device. These and other aspects of embodiments aredescribed in more detail below.

Some embodiments include an apparatus for mitigating a visual defect inan electronic device on a substrate, the apparatus including: a firstmechanism configured to detect the visual defect; and a second mechanismconfigured to mitigate the visual defect. Apparatus described herein areparticularly useful for identifying and mitigating visual defects wherethe electronic device on the substrate is an electrochromic window pane.In some embodiments, the first mechanism and second mechanisms aremounted on a movable stage, the movable stage configured to align thefirst and second mechanisms over all or substantially all of theviewable surface of the substrate. In one embodiment, the movable stageis an X-Y stage.

In some embodiments, the first mechanism includes an optical instrument.The optical instrument may be automated and thus include associatedoptical processing software. In one embodiment, the optical instrumentincludes at least one of a microscope, a camera, and a photo detector.For example, a microscope finds the center of a halo by measuring therelative intensity of light passing through the window (including anydefects) and zeroing in on the maximum intensity region, which willtypically be the center of the halo, and which also indicates thelocation of the defect to be remedied. Other types of detectionmechanisms may rely on reflection or scattering of incident light (e.g.laser light, high intensity lamps, or ambient light). A microscope wouldtypically be used during bright daylight hours when external radiationis impinging on the window undergoing defect detection; however a brightlight or other source of visible energy, e.g. a laser source, may beused to illuminate the pane from the other side during darker hours ofthe day.

In some embodiments, a dark field illumination technique may be used todetect defects. In dark field illumination, sample contrast comes fromlight scattered by the sample. A dark field illumination technique canwork well for defect detection when the defect causes a bump or othersurface irregularity on the substrate; the dark field illuminationtechnique can improve the contrast of such defects. For example, in thecase of an electrochromic device disposed on a lite, the defect couldinclude a particle with layers of the electrochromic device depositedover it, forming a raised bump in the electrochromic device.

As shown in FIG. 4, in dark field illumination, a substrate, 480, mayinclude a particle, 481, creating an irregularity on the surface ofsubstrate 480. Illumination sources, 482 and 483, may illuminateparticle 481 at a small glancing or grazing angle (e.g., angles 484 and485). An optical detector, 486, may detect light scattered from theirregularity on the surface of substrate 480. In some embodiments, darkfield illumination employs a lens or other optical component to focusthe scattered light onto optical detector 486.

Light incident upon the smooth regions of substrate 480 would reflect atwide reflection angles and would not be collected optical detector 486.In some embodiments, when multiple light sources or a circular lightsource (i.e., a light source configured to shine light from a perimeterof a circle onto a substrate) are used, the scattered light may form animage of the irregularity contour. In some embodiments, when a single oronly a few light sources are used, the scattered light may give anindication of a surface irregularity, but may not form an image of thesurface irregularity. In some embodiments, the first mechanism includingcomponents for dark field illumination may be on the same side of thesubstrate or lite as the second mechanism.

In some embodiments, the second mechanism includes at least one of alaser, a heat source, an induction coil, a microwave source, and avoltage source. If a laser is used, some thought must be given toensuring the safety of those who might encounter the laser beam outsidethe building having a window where the remediation is being performed.In one embodiment, a laser having a very short focal length laser beamis used to mitigate defects so that any laser radiation passing outsidethe window will quickly diffuse over a wide area and become harmless. Inone embodiment, laser energy is used to circumscribe a visual defect insuch a manner so that it penetrates at least through the entireelectrochromic device, including the electrochromic materials and bothtransparent conducting layers. The penetration may or may not passthrough a diffusion barrier (if present) on the substrate. In anotherembodiment, mechanisms that allow detection and remediation after darkare used, so that there is a much lower likelihood of escaping laserradiation injuring citizens. In another embodiment, an opaque materialis draped over the opposite side of the window upon which remediation isto take place. In another embodiment, the laser is tuned so that uponencountering the EC device and while mitigating the defect, theremaining energy of the laser beam is scattered or otherwise madediffuse so that any energy traveling past the window pane is harmless.

In some embodiments, a combination laser backstop/illumination device isused when the second mechanism includes a laser. A laserbackstop/illumination device may be a battery powered device that isattached to the opposite side of the window from the laser during defectmitigation. For example, an illumination device may be useful inlocating visual defects in an electrochromic device disposed on awindow. The electrochromic device may be transitioned to a coloredstate, with the illumination device on a first side of the window and anoptical instrument for detecting defects may be on a second side of thewindow. The illumination device, by shining light though pinholes orother visible defects in the electrochromic device, may make suchdefects more visible. In some embodiments, the illumination deviceincludes a diffused light emitting diode (LED) backlight, a diffusedhalogen lamp, or other means of projecting light directly through theelectrochromic device. For example, in some embodiments, theillumination device may include optics or components that use ambientlight, including ambient sunlight, for a light source.

The illumination device is coupled with a laser backstop that mayinclude a safety interlock. The illumination device would be protectedagainst laser damage by an optical band-reject filter or other opticalcomponent that would block the wavelength of electromagnetic radiationof the laser.

In some embodiments, a laser backstop/illumination device and a laserinclude an active communication system. The communication system may bepowered by a battery. For example, the communication system may includeoptical transceivers, inductive proximity detectors, or other means ofwireless connection between the laser backstop/illumination device andthe laser. When the communication system indicates that the laserbackstop/illumination device and the laser are in close proximity to oneanother, on either side of the window, the laser backstop is in aposition to block laser light and the laser is enabled. When thecommunication system indicates that the laser backstop/illuminationdevice and the laser are in not close proximity to one another, thelaser is not enabled. The default mode would be the laser not beingenabled.

When using an apparatus for detecting and mitigating defects, with theapparatus including a laser backstop/illumination device, the apparatuscould be operated by a single person or, for example, two or morepeople. For example, when one person is operating the apparatus, theuser could attach the laser backstop/illumination device on an outsideof a window on a building and then use the apparatus for mitigatingdefects. When two people are operating the apparatus, the people couldwork as a team; one person could be on the outside of the building andmove the laser backstop/illumination device, and one person could beinside the building operating the apparatus.

In certain embodiments, apparatus described herein are portable.Generally, portable apparatus for identifying and mitigating defectsshould affix to or otherwise be held in position with respect to thewindow during operation. The associated mechanism for positioning mayinclude, for example, a suction cup device that engages the frame orother structural feature around the window. In another mechanism, theapparatus is mounted on a rollable cart which has a verticallyadjustable positioning mechanism for positioning the detection andremedying mechanisms during defect detection. This cart is wheeled orotherwise placed in position adjacent to a window undergoing defectdetection and mitigation. Other positioning mechanisms are describedbelow. In one embodiment, a portable defect mitigator is a handhelddevice having the features of a portable defect mitigator describedherein.

Referring to FIG. 5A, a portable defect mitigator, 400, is depicted inperspective. Defect mitigator 400 has a frame, 405, which houses an X-Ystage including rails 410 and 415, along with other drive components(not shown), which allows base 430 to be positioned horizontally andvertically within frame 405. In this example, base 430 is rotatableabout a central axis as depicted, and supports a defect detector, 420,such as an optical microscope, and a defect mitigator, 425, such as alaser. In this example, detector 420 and mitigator 425 are bothsupported on an arm which connects to base 430. In certain embodiments,apparatus described herein also include components for translating thedefect detector and/or the defect mitigating component in theZ-direction, that is, toward and away from the window pane to berepaired. This may be necessary, e.g., when a laser or other focusedbeam mechanism is used to mitigate a defect in order to focus and/orposition vertically within the stack, or attenuate the amount of energyapplied to the electrochromic device.

Defect mitigator 400 also includes a controller, 440, in this example anonboard controller. In this example, electrical communication betweencontroller 440 and detector 420 and mitigator 425 is hardwired asdepicted. Base 430 has appropriate electrical connections, e.g.,rotating electrical transfer components (commutator), which allow it tobe rotatable while providing electrical communication between thecomponents it supports and controller 440. Electrical communicationbetween base 430 and controller 440 would also include, e.g., wireshoused within rails 415 and 420 and appropriate electrical connectionsthat allow the rails to translate while maintaining the electricalcommunication (the wires may also be outside the rails with appropriatemeasure to prevent entanglement with moving parts of the apparatus). Inother embodiments wireless communication between the controller anddefect detector and mitigator components is used. As one of ordinaryskill in the art would appreciate, controller 440 has appropriate logicto send instructions to, and receive instructions from, the defectdetector and mitigator components 420 and 425. Controller 440 may alsocontain memory, drivers for movement components, logic and the like.

In one embodiment, logic for controllers described herein includes: afirst algorithm for scanning the electrochromic window pane with thefirst mechanism in order to detect the visual defect; and a secondalgorithm for positioning the second mechanism appropriately in order tomitigate the visual defect. In one embodiment, the first algorithm usesat least one of reflection, scattering and refraction, in order toidentify a defect signature. The first algorithm may includeinstructions for scanning the entire surface of the viewable area of theelectrochromic pane and assign coordinate data for each visual defectidentified. The coordinate data may be stored in a memory and used bythe controller to send instructions to the defect mitigator component.The coordinate system and window pane dimensions may be preprogrammedinto the controller logic. In one embodiment, the logic includesinstructions to scan the window to determine the window's viewable areaand then establish a coordinate system based on the dimensions of thewindow, and e.g. the scanning device's limitations and/or operatingparameters.

In certain embodiments, the second mechanism, the defect mitigatorcomponent, includes a laser and the second algorithm includesinstructions for guiding the laser in order to circumscribe damage tothe electrochromic device which is the underlying cause of the visualdefect. In certain embodiments, all of the coordinates of the identifiedvisual defects are stored in a memory and this information is used bycontroller logic to appropriately position the defect mitigatorcomponent in order to circumscribe each defect. The logic may includeinstructions for identifying all the defects prior to any mitigation,or, in some embodiments, each defect is identified and then mitigated,before moving on to identify more defects. In one case, the logic mayinclude metrics used in automated identification of a defect, type ofdefect, and prioritization of the defects for mitigation. These metricsmay be based on the size, shape, centroid location, and othercharacteristics of the defects.

As noted on the right hand side of FIG. 5A, apparatus 400 includes feet,435, which attach frame 405 to, e.g., a wall in which an electrochromicwindow, 450, is installed. In this example, frame 405 of apparatus 400is larger than window 450 so that the X-Y stage can be manipulated toposition defect detector 420 and defect mitigator 425 over all areas ofthe glass of electrochromic window 450 in order to scan for and mitigatevisual defects wherever they may be on the viewable area of the glasspane bearing the electrochromic device to be repaired (movement in the Zdirection can be preset and defined once apparatus 400 is in placeand/or in one embodiment there is a Z-positioning mechanism for 420and/or 425). Feet 435 may be, e.g., suction cups, pressure-sensitiveadhesive pads and the like. In certain embodiments, it may be necessaryto attach apparatus 400 to the wall or window frame in a more securefashion, e.g. via a temporary support such as one or more wall anchors,a z-bar or the like. Apparatus 400 may also include clamps, hooks orother components that allow it to hang over a window frame, supportitself by clamping between bricks along a mortar line, and the like. Insome embodiments, apparatus 400 is supported by legs, a tripod, a stand,a table, a cart or the like, whether or not it is also supported by awall. In one embodiment, apparatus 400 is supported by one or morevertical supports, such as posts, where the posts are compressivelypositioned between the floor and ceiling, whether or not apparatus isalso supported by a wall. One of ordinary skill in the art wouldappreciate that combinations of support mechanisms are within the scopeof embodiments described herein. Polymeric suction cups,pressure-sensitive adhesive pads and other similar attachment mechanismshave the advantage of simplicity and dampening any vibrations that mightotherwise travel between apparatus 400 and the surface to which it isaffixed.

In one embodiment, the apparatus, e.g. as described in relation to FIG.5A, does not affix to the wall or window, but rather frame 405 ismovable along tracks or rails so that it can be moved, or viaappropriate movement mechanisms. This is illustrated in FIG. 5B. A wall,460, contains a number of windows in a linear arrangement, in thisexample a horizontal arrangement, but it could also be a verticalarrangement. A system of rails, 455, is established, e.g., affixed towall 460, or e.g., compressed between adjoining walls to wall 460, ore.g. supported by stands at distal ends of the rails, etc. Rails 455 mayhave a circular cross section as depicted, or have rectangular,triangular or other geometric cross sections for added strength anddecreased tendency to bend or otherwise deform while apparatus 400 isoperating thereon. Apparatus 400, via appropriate movement mechanisms,“walks” along rails 400, scanning each window 450, identifying visualdefects and mitigating them. This configuration has the advantage thatan initial set up of the rail system will allow the apparatus to repaira number of windows, e.g. in a curtain wall, automatically withouthaving to perform an alignment of apparatus 400 for each windowindividually. In one embodiment, apparatus 400 travels along rails ortracks 455 where contact with the rails is made via wheels having apolymeric component, e.g. polymeric wheels or hard wheels with apolymeric covering, such as nylon or silicone in order to minimizevibration during identification and mitigation. Although apparatus 400in its entirety is not typically moving during identification andmitigation of defects, there may be vibration from the wall or otherbuilding component to which the rail system is attached.

As mentioned, in this example, apparatus 400 is larger thanelectrochromic window pane in window 450 for the described reasons. Inone embodiment, the largest dimension of the apparatus is notsubstantially larger than the largest dimension of the electrochromicwindow pane. In one embodiment, the largest dimension of the apparatusis not more than about 20% larger than the largest dimension of theelectrochromic window pane, in another embodiment, not more than about10% larger than the largest dimension of the electrochromic window pane.In certain embodiments, described in more detail below, the largestdimension of the apparatus is the same or smaller than the largestdimension of the electrochromic window pane to be repaired. In oneembodiment the apparatus is smaller than the electrochromic pane forwhich it is intended to repair. That is, the dimensions described aboveare meant to provide a metric for apparatus that use some form ofattachment to a window and/or a wall, or that otherwise have a framethat is aligned in some way with the window to be repaired, for example,a frame containing an X-Y stage as described. As described above, incertain embodiments, apparatus are supported by a tripod, a cart, atable or the like, that does not affix to a window or wall.

In one embodiment, a handheld defect mitigator includes a defectdetector, a defect mitigator and a controller, each as described herein,in a handheld configuration. A handheld defect mitigator may require twohands or only one hand to operate. Typically, but not necessarily, thehandheld defect mitigator includes Z-direction positioning mechanism,which can be adjusted to particular needs, e.g., when mitigating througha non-EC pane of an IGU or directly through only the EC pane of the IGU.A handheld defect mitigator may have suction cups or adhesive pads tosecure the apparatus to the glass at least during mitigation. In thiscontext, a handheld defect mitigator may not use and/or include anautomated X-Y positioning mechanism, but rather would rely on handpositioning at least to initially position the apparatus over a defect.After initial positioning, there may be some finer positioning handoperated mechanisms to move in the X-Y plane, such as thumbscrewadjustments and the like, to zero in on a defect. The optical instrument(e.g. a microscope) and mitigating mechanism (e.g. a laser) may bemanually operated, or automatic once in position.

In some embodiments, a portable defect mitigator has an optical systemwith an optical detector, a laser and/or an illumination source sharinga coaxial optical path. FIG. 5C is a schematic drawing of components ofa portable defect mitigator having an optical system 550 including alaser 555 and an optical detector 560. In this illustrated example,laser 555 and optical detector 560 having a co-axial optical path. Insome cases, optical detector 560 includes a charge coupled device (CCD).Also shown in FIG. 5C is an IGU, 565, including two panes or lites, withan electrochromic device, for example, disposed on a surface, 570. Theoptical components of optical system 550 further include a first mirror,575, a dichroic mirror, 577, and lenses, 579 and 581. Lens 579 may be anobjective lens and lens 581 may be a condensing lens.

In operation, the electrochromic device disposed on surface 570 of IGU565 may be transitioned to a colored state. An illumination device, 585,may be positioned to shine light though any defects in theelectrochromic device. Light from illumination device 585 would reflectfrom first mirror 575 about 90 degrees, pass though lens 579, passthough dichroic mirror 577, pass though lens 581, and form an image ofthe defect that is detected by optical detector 560. Dichroic mirror 577is specified such that the wavelength or wavelengths of light fromillumination device 585 pass though the dichroic mirror. When opticaldetector 560 detects a defect, the defect may then be mitigated withlaser 555.

In this example, light from laser 555 would reflect from dichroic mirror577 about 90 degrees, pass though through lens 579, reflect from firstmirror 575 about 90 degrees, and then impinge on surface 570. Dichroicmirror 577 is specified such that the wavelength of light from laser 555is reflected by the dichroic mirror. Lens 579 focuses the light fromlaser 555 to a focal point on or near to surface 570 to concentrate theenergy of the light to mitigate the defect.

Lens 579 may be adjusted to change the focal point of both laser 555 andoptical detector 560. The focal plane of both the laser and the opticaldetector would be finely tuned to match by adjusting the position oflens 581. Thus, optical system 550 and other similar optical systemswith a laser and an optical detector having a coaxial optical pathallows the laser to be aimed at a defect and provides accurate alignmentbetween the detection and mitigation processes.

In some embodiments, optical system 550 has a low mass. Because opticalsystem may be mounted directly to a window, it is desirable to keep boththe mass of the system and the moment perpendicular to the window low toprevent deflection of the window during operation of the system. Forexample, laser 555 may include a fiber coupled input with a low masspresenting a small perpendicular moment, with the laser source beingmounted elsewhere (i.e., not on the window). Further, with one lens,lens 579, used to focus both laser 555 and optical detector 560, asingle motor may be used to adjust the lens, reducing the mass ofoptical system 550. Optical system 550 may be positioned close to IGU565 or other window while still keeping the majority of the mass alongthe vertical axis of the window.

One goal of the coaxial optics in optical system 550 is for thedetection path and the laser path to “see” the defective surface asidentically as possible. This facilitates the precise removal of thedefect with minimal error in laser alignment. Even with coaxial optics,however, there may be alignment errors of the laser focal pointassociated with diffraction through the glass of the IGU, aberrations ina lens, glass warpage, the wavelength dependence of optics in theoptical system, etc. These errors may create an offset between thecenter of the detection optics path and the center of the laser opticspath, leading to laser alignment errors.

To remedy this, in some embodiments, optical system 550 may include acontroller including program instructions for conducting a process. Theprocess may include a low power firing sequence with the laser to ensurethat the laser focal point is at the position of the detected defect.For example, in some embodiments, optical system 550 is aligned on adefect using the optical detector 560. Then, laser 555 emits light at alow power to create a visible spot of light on surface 570 which isreflected and imaged by optical detector 560. There may be an offsetbetween where the defect is detected by optical detector 560 and thevisible spot of light from laser 555 as shown in diagram 590 of FIG. 5D.The controller can then determine the exact positional offset betweenwhere the laser light is intended to intersect surface 570 during defectmitigation and where it actually will intersect surface 570. Thealignments of optical system 550 is then adjusted to correct for anyerror in alignment prior to firing the laser at high power to mitigatethe defect, as shown in diagram 595 of FIG. 5D.

Referring to FIG. 6, a portable defect mitigator, 500, is depicted inperspective. Unlike defect mitigator 400, defect mitigator 500 does nothave a frame, or an X-Y stage along with other drive components. Likeapparatus 400, apparatus 500 does have a base 430 which is rotatableabout a central axis as depicted, and supports a defect detector, 420,such as an optical microscope, and a defect mitigator, 425, such as alaser. In this example, detector 420 and mitigator 425 are bothsupported on an arm which connects to base 430. Base 430 is supported bya column, 505. Column 505 is movable along a vertical axis through anaperture in a body 515. Body 515 houses a controller 525, similar tocontroller 440 described above. In this example, via a drive mechanism,510, column 505 is translated vertically, up or down through body 515,which is stationary and rests on legs 520. Controller 525 has a logicthat performs the identification and mitigation of defects as describedabove in relation to apparatus 400; however, the movement algorithms forpositioning detector 420 and mitigator 425 are different with respect tocolumn 505 as compared to apparatus 400 which has an X-Y stage movementassembly (movement in the Z direction can be achieved manually in thiscase by appropriate placement of the tripod). In certain embodiments,which is true for all apparatus described herein, positioning, scanningand mitigation commands can be input manually, e.g., via a keypad orother input device on the controller. In some embodiments, once theapparatus is positioned and/or aligned, these functions are fullyautomated, that is, the apparatus automatically scans the window pane,identifies the visual defects according to programmed criteria andmitigates the visual defects. Apparatus 500 may also include componentsfor translating the defect detector and/or the defect mitigatingcomponent in the Z-direction, that is, toward and away from the windowpane to be repaired as described in relation to apparatus 400.

During operation, apparatus 500 is positioned and aligned appropriatelyin front of window 450 so that detector 420 and mitigator 425 can scanand identify and mitigate visual defects across the entire viewable areaof electrochromic window 450. Apparatus 500 has the advantage of beingcompact relative to, e.g., an apparatus having a large frame and X-Ystage, e.g., legs 520 may be telescopic and foldable when not in use.

In some embodiments, the largest dimension of the apparatus is smallerthan the largest dimension of the electrochromic window pane and theapparatus mounts to the electrochromic window that includes theelectrochromic pane during operation. In one embodiment, the apparatusmounts to the window pane (glass) itself, without having to touch thewindow frame or wall. In this embodiment, the apparatus may attach tothe window via at least one of a suction cup and a pressure-sensitiveadhesive. This may include a handheld defect mitigator as describedherein (e.g. an apparatus not having an X-Y stage positioningcomponents).

Referring to FIG. 7, a portable defect mitigator, 600, is depicted inperspective. Like defect mitigator 400, defect mitigator 600 has aframe, and an X-Y stage along with other drive components. Also, likeapparatus 400, apparatus 600 has a base 605; however base 605 isnon-rotatable. In this example, base 605 is a frame through which thedetector component can scan the pane of window 450 to locate andidentify visual defects and the mitigator component can mitigate thedefects. The X-Y stage in apparatus 600 moves base 605 about the areainside the frame 615 of apparatus 600. Although apparatus 600 cannotidentify and mitigate defects over the entire area of window 450 whilein a single position, it has the advantage of being small and moreeasily ported to the jobsite. In some instances, a customer might haveonly a few halo effects on a window, or windows, and such an apparatuswould be more easily positioned over the halo in question forremediation efforts. In this example, referring to expanded portion X inFIG. 7, wireless communication is used between detector/mitigatorcomponents and controller 610. One embodiment is any apparatus describedherein, e.g. apparatus 400 or 500, further including wirelesscommunication between the detector and/or mitigator and the controller.One of ordinary skill in the art would appreciate that such apparatuswould include appropriate wireless antennae, receivers and transmitters.The controller need not be affixed to the frame or other component ofthe apparatus; rather it can be in the form of a remote control device.

One embodiment is a method of mitigating a visual defect in anelectrochromic window installed in a building or an automobile, themethod including: (a) identifying the visual defect in theelectrochromic window; and (b) mitigating the visual defect using atleast one of a laser, a heat source, an induction coil, a microwavesource and a voltage source. In one embodiment, the electrochromicwindow is colored prior to (a) or as part of the identification process.Apparatus as described herein are particularly useful for implementingmethods described herein.

FIG. 8A depicts aspects of a method, 700, which begins with identifyinga visual defect, see 705. As described, apparatus described herein, oncepositioned appropriately, may scan an electrochromic pane in order tolocate and identify visual defects. FIG. 8B outlines an embodiment ofprocess flow 705. First the electrochromic pane is colored, see 715. Thedefect detector is then positioned with respect to the pane, see 720.Steps 715 and 720 may be done in reverse order or simultaneously. If thepane is already colored, then step 715 is optional. Next, theelectrochromic pane is scanned, see 725. As described above, this may beaccomplished with controller logic having instructions for particularscanning algorithms. Optionally, the coordinates of the visual defectmay be stored in a memory, e.g., part of the controller, see 730. Next,e.g. when a controller logic is used, the coordinates of the visualdefect may be communicated to the defect mitigator mechanism, see 735.Then the identification operations end.

Referring back to FIG. 8A, after the visual defect is identified, it isthen mitigated using the mitigation mechanism, see 710. FIG. 8C outlinesan embodiment of process flow 710. Assuming the visual defect'scoordinates were sent to, e.g. a mitigation mechanism, the data isreceived by the mitigation mechanism, see 740. The defect mitigationmechanism is then positioned with respect to the electrochromic paneappropriately to mitigate the defect, e.g., circumscribe the defect witha laser, see 745. Once positioned, the defect is mitigated, see 750.Then the process flow ends.

In certain embodiments, a laser is used to mitigate a defect.Electrochromic windows may have an EC device on the inner surface of theouter (on the outside of a building) pane of glass, while the inner panedoes not have an associated EC device. Lasers are particularly usefulfor mitigation because they can be tuned so that the laser beam ispassed through the inside pane of glass in order to mitigate a defect inthe EC device on the outer pane (e.g. inside a window unit, two paneswith a separator between them, e.g. a simple IGU). One embodiment is amethod of mitigating a visual defect in an electrochromic device on aglazing that is part of a window unit, the method including: (a)identifying the visual defect in the electrochromic device; and (b)mitigating the visual defect using a laser. In one embodiment, theelectrochromic device is colored prior to (a) or as part of theidentification process. In one embodiment, the window unit is an IGUhaving a first and a second pane (glazing), where the first pane bearsan electrochromic device and the second pane does not have anelectrochromic device thereon. In one embodiment, the laser energy ispassed through the second pane and a defect in the electrochromic deviceon the first pane is mitigated. In one embodiment, the laser energy ispassed through the first pane and a defect in the electrochromic deviceon the first pane is mitigated.

Mitigating defects using laser energy that passes through a pane of anIGU, through the volume of the IGU and ablates an electrochromic deviceon an opposing pane is different than mitigating defects in anelectrochromic device sealed in a laminated structure, e.g., asdescribed in U.S. Pat. No. 7,531,101. For example, in such laminatedstructures, there is necessarily an interlayer material such as athermoplastic polymer material that binds the substrates together. Thismaterial can affect the ability to ablate an electrochromic device ifthe laser energy must pass through the interlayer material, for examplethe interlayer material may be an absorber of the laser energy. Forexample PVB and polyurethane interlayer materials may absorb certainwavelengths of energy. Also, due to the distance between the panes of anIGU in the volume of the IGU, the focal distance, power and choice oflaser may vary considerably.

In certain embodiments, apparatus and methods herein are used toidentify and mitigate defects in electrochromic windows that have atleast one EC device on both the inner and the outer pane of the IGU.Electrochromic windows having this architecture are described in U.S.patent application Ser. No. 12/851,514, filed Aug. 5, 2010, andentitled, “Multi-pane Electrochromic Windows,” by Friedman et al., whichis incorporated by reference herein in its entirety. When defects insuch windows are mitigated, for example a window having one EC device oneach pane of an IGU, identification and mitigation of defects aretypically, but not necessarily, carried out while one pane's EC deviceis bleached so that the other pane's EC device can be colored and anydefects identified and mitigated. Once one pane's defects are mitigated,the EC device on the processed pane is bleached and the other pane iscolored in order to carry out identification and mitigation operationson that pane. Identification and mitigation may be carried out from asingle side of the window, for example the interior of the building,because the inner pane can be bleached and the laser tuned to passthrough the bleached pane and mitigate the outer pane's colored ECdevice.

Dynamic Autofocusing System

Although windows are substantially rigid, they may have some degree offlex under certain circumstances. For example, an electrochromic window,particularly a large electrochromic window, may flex somewhat whilebeing installed and when subject to external forces such as wind. If anelectrochromic window flexes during the course of defect imaging andmitigation, the maximum flux of radiant energy at the focal point of thelaser may not remain aligned to the targeted portion of the window.Typically, the focal point should be targeted to a position at or verynear the surface of the electrochromic device near the defect. If thefocal point of the laser does not remain aligned to the targetedlocation, defect mitigation (and/or imaging) may become less effective.Dynamic autofocus systems disclosed herein can be employed by the defectmitigator to help ensure that the focal point of the laser remainsconsistently aligned to the targeted location even while the window maybe flexing or otherwise moving over the course of the imaging andmitigation process.

One way that a dynamic autofocus system can address this challenge is byautomatically adjusting the position of a lens to focus the laser lightto the targeted location as the window flexes or otherwise moves duringdefect imaging and/or mitigation. For example, the lens can beautomatically adjusted to maintain the lens at a particular separationdistance D (e.g., a distance at about a focal length of the lens fromthe surface) from the targeted location or maintain the lens within arange of distances from the particular separation distance D from thetarget location. The target location is typically at a surface of theelectrochromic device having the defect.

In some cases, these automatic adjustments can be accomplished with asuitably fast feedback/control system. This system includes a processor(e.g., microprocessor) that sends signals to a lens positioningmechanism capable of moving the lens in response to certain detectedmovements of the surface of the electrochromic device or other suitableportion of the window. The processor is in communication with adetecting mechanism that detects these movements.

During defect mitigation, the processor may receive signals with datafrom the detecting mechanism. The data may include the location of thesurface or other portion of the window at the time of detection. Theprocessor may determine the current separation distance D and/or themovement of the window since the last sampling time. The processor maythen determine whether the current separation distance D (or movement)at the time of detection requires that the lens move to correct theposition of the focal point at the targeted portion of the window. Forexample, the processor may determine whether the difference between thecurrent separation distance D and the focal length of the lens is morethan certain percentage difference (e.g., 0.001%, 0.01%, 0.1%, 1%, 2%,etc.) to determine whether the difference is within an acceptable range.As another example, the processor may determine whether the differencebetween the current separation distance D and the focal length of thelens is more than a maximum difference (e.g., 0.01 mm, 0.1 mm, 0.2 mm,etc.) to determine whether it is within an acceptable range. If thesurface has moved out of the acceptable range, the processor determinesa new location of the lens with a separation distance D within theacceptable range. For example, the new location may be a distance (fromthe current location) equal to the measured separation distance D lessthe focal length. The processor then sends a control signal to the lenspositioning mechanism 1020 to move the lens to the new location.Dynamically adjusting the lens to maintain the separation distance Dwithin this acceptable range, keeps the laser in focus substantiallylocating the focal point at the target location for mitigating thedefect. The acceptable range may be related to the size and centroidlocation of the focal point of the laser being employed.

In some instances, there may be a significant lag time between thesample time at which the separation distance is measured and the time atwhich the lens has moved to the new location. To lessen the impact ofsuch a lag time, certain embodiments of the portable defect mitigatormay include a processor that can predict a separation distance D at afuture time based on measurements from the detection mechanism (e.g.,triangulation sensor) taken at one or more sample times. In these cases,the detection mechanism may determine the separation distance D and arate of change of the separation distance D at a sample time. Theprocessor can determine the future separation distance D at a futuretime based on the separation distance D and rate of change measured atthe sample time. If the surface is predicted to move out of theacceptable range by the future time, the processor can determine a newlocation of the lens with a separation distance D within the acceptablerange that is appropriate for the future time. The processor then sendsa control signal to the lens positioning mechanism 1020 to move the lensto the new location and the lens moves to the new location by the futuretime.

FIG. 9 is a schematic illustration of a mitigation process using adynamic autofocus system 1000, according to embodiments. In thisexample, the mitigation process is being performed on a window unit 910having a first electrochromic window pane 920(a), a secondelectrochromic window pane 920(b), and a sealing separator 930 betweenthe first and second panes 920(a), 920(b). The first electrochromicwindow pane 920(a) has a first surface 922(a) and a second surface922(b). The second electrochromic window pane 920(b) has a first surface924(a) and a second surface 924(b). Each of the electrochromic windowpanes 920(a), 920(b) includes an electrochromic device on one side orboth sides of a substantially transparent sheet (e.g., glass sheet). Theillustrated window unit 910 may be part of an IGU. Although anelectrochromic window is shown in FIG. 9 and other illustratedembodiments, any window with an optically switchable device can be used.

In FIG. 9, a wind force 1010 is impinging the second surface 924(b) ofthe second electrochromic window pane 920(b). The wind force 1010 iscausing the window unit 910 to bend and bow inward at the centerportion. The illustration shows the window unit 910 at two instancesbefore flexing 910(1) (at time t₀) and after flexing 910(2) (at time t₁occurring during the mitigation process). Although a wind force is usedin embodiments, other forces may cause deformation of the window panes.For example, building vibrations from a train or construction may causedeformation.

The illustrated dynamic autofocus system 1000 includes a lenspositioning mechanism 1020, a detection mechanism 1030, and a processor1040 in communication with the lens positioning mechanism 1020 and thedetection mechanism 1030. A laser (not shown) provides a collimatedlaser beam 1050 used to mitigate the defect. The lens positioningmechanism 1020 is in communication with a lens 1060 used to focus thecollimated laser beam 1050 to a focal point 1070. The focal point 100 islocated at or near a target location for mitigating the defect. In thisexample, the target location is at the second surface 924(b) of thesecond electrochromic pane 920(b). In other embodiments, the targetlocation may be at other locations of the window unit 910.

During the mitigation process illustrated in FIG. 9, the detectionmechanism 1030 measures the location of the second surface 924(b) and/oranother surface (e.g., 924(a), 922(a), 922(b)) at different samplingtimes, t₁, t₂, . . . , t_(n). Alternatively, the detection mechanism1030 may measure the location of the target portion. At each samplingtime, the detection mechanism 1030 sends signals to the processor 1040with the location data. In the illustration, the detection mechanism1030 measures the location of the second surface 924(b) near the defectat time t₁ and sends signals with data to the processor 1040 with thelocation at time t₁. The processor 1040 sends control signals to thelens positioning mechanism 1020 to move the lens 1060 from a firstposition to a second position along a z-axis located along thecenterline axis of the collimated laser beam 1050. This movement keepsthe separation distance D between the target location at the secondsurface 924(b) and the lens 1060 to a constant value equal to the focallength to keep the focal point 942 at the second surface 924(b) duringthe mitigation process. In other examples, the detection mechanism 1030may detect a location on multiple surfaces or other surfaces of thewindow. In some cases, the surface detected by the detection mechanism1030 may correspond to the closest surface to the defect.

As explained, the maximum flux of radiant energy (at the focal point)should be located at the targeted portion of the electrochromic deviceto be mitigated. Another possible way to address this challenge involvesusing a laser beam that is relatively insensitive to changes in distanceD. Such a beam would have a relatively long focal point (i.e., long inthe direction of beam propagation). The focal point length would begreat enough to permit mitigation over the full range of variations in Dencountered during movement of the electrochromic window. The length ofthe beam that provides a relatively invariant radiant energy flux (thefocal region) is sometimes referred to as the “depth of focus” of thebeam. Achieving a depth of focus of greater than about ±500 μm (i.e.,greater than 1000 μm total depth) is typically problematic. A depth offocus this great may make the spot area of the laser beam too great toeffectively scribe. Further, the separation distance of the laser optics(e.g., the condensing lens) from the tool may be too great. In someembodiments, suitable depth of focus ranges are about ±100 μm or less,or about ±50 μm or less. Therefore, the depth of focus of a laser istypically too short to allow the system to operate without adjusting thelens position in order to maintain a separation of D.

Various possible focus control mechanisms that can be employed as adetection mechanism 1030 in the dynamic autofocus system to ensure thatthe focus of the laser remains focused during mitigation at the properheight (e.g., z-position in FIG. 9) through the thickness of the window.One type of design employs confocal detection and patterning beams. Adetection beam is used to determine the distance between the surface ofinterest and a frame of reference. Generally a confocal system is onewhere the patterning and detection beams (or any other two beams) sharethe same focal point. They may, in some embodiments, share the sameoptics.

Another type mechanism that may be used as a detection mechanism 1030 inthe dynamic autofocus system 1000 is a triangulation sensor. Someexamples of triangulation sensors that can be employed as detectionmechanisms 1030 can be found in U.S. patent application Ser. No.13/436,387, filed on Mar. 30, 2012, which is hereby incorporated byreference in its entirety. FIG. 10 illustrates an example of atriangulation sensor 1132 that can be used as a detection mechanism inthe dynamic autofocus system, according to embodiments. Thetriangulation sensor 1132 includes a laser 1133 and a detector 1134. Insome embodiments, laser 1133 may be a lower power laser that does notscribe or melt a substrate, but is reflected from the substrate. In manycases, the laser 1133 is a blue laser. In some cases, the detector 1134may be a charge coupled device (CCD). Detector 1134 is positioned toface a direction at a fixed angle from laser beam path. Thetriangulation sensor 1132 may be mounted to the same block that holdsthe focal lens.

In operation, triangulation sensor 1132 projects a laser beam from laser1133 onto a surface of an electrochromic window. The laser beam isreflected from the surface and onto different regions of detector 1134.From the region of detector 1134 that the laser beam is reflected onto,the distance of the surface of the electrochromic window fromtriangulation sensor 1132 can be determined. For example, as theelectrochromic window moves in the z-direction along a z-axis at thecenterline of the laser beam propagation, the lateral movement asdetected by detector 1134 is converted to a distance reading betweentriangulation sensor 1132 and the surface of the electrochromic window.

Triangulation sensor 1132 can determine a distance of a surface of theelectrochromic window from triangulation sensor 1132 and or the distanceof the surface of the electrochromic window to the focal lens of thedynamic autofocus system 1000. For example, triangulation sensor 1132may determine a nominal distance s₀ from the surface at a position 1136at height of z=0 where the electrochromic window is in a baseline state(not flexing or otherwise moving). As another example, triangulationsensor 1132 may determine a distance s₁ from the surface at a position1137 at height of z=+z₁ where the electrochromic window flexed and theposition has moved in the positive z-direction by z₁. As anotherexample, triangulation sensor 1132 may determine a distance s₂ from thesurface at a position 1138 at height of z=−z₁ where the electrochromicwindow flexed and the position has moved in the negative z-direction byz₁. In some cases, the triangulation sensor 1132 may be restricted tomeasuring distances between a minimum distance and a maximum distance.In these cases, the triangulation sensor 1132 may be set or calibratedbased on the nominal distance.

In one embodiment, the dynamic autofocus system adjusts the focus lens1060 such that the beam emitted from the laser impinges a second side ofthe second side of the electrochromic pane and is focused at theinterface of the first side of the electrochromic pane and theelectrochromic device, as determined by the triangulation-based distancesensor 1132. For example, a feedback loop may be implemented such thatthe focus lens 1060 adjusts rapidly based on the determination by thetriangulation-based distance sensor. In some embodiments, a signal fromthe triangulation-based distance sensor 1132 may be an analog signalwhich may aid in enabling the rapid adjustment of the focus lens 1060.

Examples of Handheld Portable Defect Mitigators

In some embodiments, the portable defect mitigator may be a handhelddesign that can be affixed directly to the surface of the window duringdefect imaging and mitigation. These handheld defect mitigators mayinclude one of the optical systems disclosed herein. Optical systemswith components in a compact arrangement that may be particularlysuitable for such a handheld design are shown in FIGS. 11A, 11B, and 12.

In FIGS. 11A and 11B, an optical system 1200 includes an opticaldetector 1210 (e.g., a charge coupled device (CCD), Complementarymetal-oxide-semiconductor (CMOS) sensor, etc.), an illumination device1212, and a laser 1220 serving as a defect mitigator. Both laser 1220and illumination device 1212 provide collimated light. Optical system1200 also includes a first lens 1230, a mirror 1234, a first dichroicmirror 1240, a second dichroic mirror 1250, and a second lens 1260. Asshown, optical detector 1210, illumination device 1212, and laser 1220share a coaxial optical path between first dichroic mirror 1240 andmirror 1234 and also between mirror 1234 and first lens 1230. Secondlens 1260 may be a condensing lens. First lens 1230 may be an objectivelens.

FIGS. 11A and 11B also include an IGU 1270 with a defect (not shown)being imaged and mitigated. The IGU 1270 has a first lite 1272 (firstpane) and a second lite 1274 (second pane) with an electrochromic devicedisposed on a surface 1276 of the second lite 1274. The defect (notshown) being mitigated is located on the surface 1276 of the second lite1274. In a defect imaging and mitigation operation, the electrochromicdevice disposed on surface 1276 of IGU 1270 may be transitioned to acolored state.

During the imaging and mitigation operation illustrated in FIGS. 11A and11B, illumination device 1212 provides collimated illumination light.The illumination light is reflected at about 90 degrees from the seconddichroic mirror 1250, and then reflected at about 90 degrees from firstdichroic mirror 1240, and then reflected at about 90 degrees from mirror1234 to first lens 1230 which focuses the illumination light. Thefocused illumination light passes through the first lite 1272 to thesecond lite 1274 of the IGU 1270. Illumination light reflected from thesecond lite 1274 to mirror 1234 will be reflected at about 90 degreesfrom mirror 1234 and then reflected at about 90 degrees from the firstdichroic mirror 1240. This light passes through the second dichroicmirror 1250 to second lens 1260. Second lens 1260 focuses the reflectedlight to the optical detector 1210. The optical detector 1210 can forman image of the defect based on light reflected from the defect area.

In FIGS. 11A and 11B, the laser 1220 emits light for mitigating thedefect. The light from laser 1220 passes through the first dichroicmirror 1240, and is reflected at about 90 degrees from mirror 1234 tothe first lens 1230. The first lens 1230 focuses the mitigating light toa focal point. The first dichroic mirror 1240 is specified such that thewavelength or wavelengths of light from laser 1220 passes through thefirst dichroic mirror 1240. The second dichroic mirror 1250 is specifiedsuch that the wavelength or wavelengths of light from illuminationdevice 1212 is reflected by the dichroic mirror 1250. First lens 1230focuses the collimated light from laser 1220 to a focal point at or nearsurface 1276 to concentrate the energy of the light to a targetedportion to mitigate the defect. First lens 1230 also focuses thecollimated light from illumination device 1212 to a focal point on ornear to surface 1276. In this optical system 1200, there is a commonaxis (coaxial path) of the laser and illumination light from the firstdichroic mirror 1240 to the mirror 1234 and from the mirror 1234 throughthe first (focal) lens 1230, and then to the focal point.

In FIGS. 11A and 11B, mirror 1234 and first lens 1230 can be rotatedtogether about a pivot point (or alternatively about one or morerotating axes) to direct the light from first lens 1230 at differentangles. This rotation allows the light to be directed at angles to beable to locate the focal point, for example, under a spacer at the edgeof an IGU or to the corner of the IGU. In FIG. 11A, mirror 1234 andfirst lens 1230 are located at a nominal position to direct the opticalpath at about a 90 degree angle to a plane substantially parallel to thesurface 1276. In FIG. 11B, mirror 1234 and first lens 1230 are tiltedupward to direct the optical path at an angle θ with respect to theplane substantially parallel to the surface 1276.

As shown, light from laser 1220 and illumination device 1212 iscollimated and along a coaxial path to the first lens 1230. Since thelight received at the first lens 1230 is collimated and coaxial, thefirst lens 1230 can focus both the mitigating and imaging light to analigned focal point. Also, moving the first lens 1230 along the opticalpath axis can control the location of the focal point of both the laserlight and imaging light. That is, the position of the first lens 1230along the coaxial optical path can be adjusted to finely focus laser1220, optical detector 1210, and illumination device 1212. The opticalsystem 1200 and other similar optical systems having a coaxial opticalpath of collimated light allow the laser to be aimed at the defect andprovide accurate alignment of the detection and mitigation processes. Inthese optical systems, laser 1220, optical detector 1210, andillumination device 1212 can be automatically focused with a dynamicautofocus system disclosed herein. To illustrate this aspect, FIGS. 11Aand 11B also include a dynamic autofocus system 1000 having a lenspositioning mechanism 1020, a detection mechanism 1030, and a processor1040 in communication with lens positioning mechanism 1020 and detectionmechanism 1030. Lens positioning mechanism 1020 is in communication withthe first lens 1230 to move the first lens 1230 to maintain the focalpoints at the same distance from the first lens 1230 as the IGU 1270 mayflex or otherwise move during the process.

In FIG. 12, an optical system 1201 includes an optical detector 1210(e.g., a charge coupled device (CCD), complementarymetal-oxide-semiconductor (CMOS) sensor, etc.), an illumination device1212, and a laser 1220 serving as a defect mitigator. Both laser 1220and illumination device 1212 provide collimated light. Optical system1200 also includes a first lens 1230 (e.g., objective lens), a firstdichroic mirror 1240, a second dichroic mirror 1250, and a second lens1260 (e.g., condensing lens). As shown, optical detector 1210,illumination device 1212, and laser 1220 share a coaxial optical pathbetween first dichroic mirror 1240 and first lens 1230. FIG. 12 alsoincludes an IGU 1270 with a defect (not shown) being imaged andmitigated. The IGU 1270 has a first lite 1272 (first pane) and a secondlite 1274 (second pane) with an electrochromic device disposed on asurface 1276 of the second lite 1274. The defect being mitigated islocated on the surface 1276 of the second lite 1274.

During the imaging and mitigation operation illustrated in FIG. 12,illumination device 1212 provides collimated illumination light. Theillumination light is reflected at about 90 degrees from the seconddichroic mirror 1250, and then reflected at about 90 degrees from firstdichroic mirror 1240 to first lens 1230 which focuses the illuminationlight. The focused illumination light passes through the first lite 1272to the second lite 1274 of the IGU 1270. Illumination light reflectedfrom the second lite 1274 to the first dichroic mirror 1240, which isreflected at about 90 degrees to second dichroic mirror 1250. The lightpasses through the second dichroic mirror 1250 to second lens 1260.Second lens 1260 focuses the reflected light to the optical detector1210. The optical detector 1210 can form an image of the defect based onlight reflected from the defect area.

In FIG. 12, the laser 1220 emits light for mitigating the defect. Thelight from laser 1220 passes through the first dichroic mirror 1240, andis reflected at about 90 degrees from mirror 1234 to the first lens1230. The first lens 1230 focuses the mitigating light to a focal point.The first dichroic mirror 1240 is specified such that the wavelength orwavelengths of light from laser 1220 passes through the first dichroicmirror 1240. The second dichroic mirror 1250 is specified such that thewavelength or wavelengths of light from illumination device 1212 isreflected by the dichroic mirror 1250. First lens 1230 focuses thecollimated light from laser 1220 to a focal point at or near surface1276 to concentrate the energy of the light to a targeted portion tomitigate the defect. First lens 1230 also focuses the collimated lightfrom illumination device 1212 to a focal point on or near to surface1276. In this optical system 1200, there is a common axis (coaxial path)of the laser and illumination light from the first dichroic mirror 1240to the mirror 1234 and from the mirror 1234 through the first (focal)lens 1230, and then to the focal point.

As shown, light from laser 1220 and illumination device 1212 iscollimated and along a coaxial path to the first lens 1230. Since thelight received at the first lens 1230 is collimated and coaxial, thefirst lens 1230 can focus both the mitigating and imaging light to analigned focal point. Also, moving the first lens 1230 along the opticalpath axis can control the location of the focal point of both the laserlight and imaging light. That is, the position of the first lens 1230along the coaxial optical path can be adjusted to finely focus laser1220, optical detector 1210, and illumination device 1212. The opticalsystem 1201 and other similar optical systems having a coaxial opticalpath of collimated light allow the laser to be aimed at the defect andprovide accurate alignment of the detection and mitigation processes. Inthese optical systems, laser 1220, optical detector 1210, andillumination device 1212 can be automatically focused with a dynamicautofocus system disclosed herein. To illustrate this aspect, FIG. 12also includes a dynamic autofocus system 1000 having a lens positioningmechanism 1020, a detection mechanism 1030, and a processor 1040 incommunication with lens positioning mechanism 1020 and detectionmechanism 1030. Lens positioning mechanism 1020 is in communication withthe first lens 1230 to move the first lens 1230 to maintain the focalpoint at the same distance from the first lens 1230 as the IGU 1270 mayflex or otherwise move during the process.

In the optical systems shown in FIGS. 11A and 11B, FIG. 12, in FIGS.13A-I, and other disclosed embodiments, the propagated light from thelaser and optical detector are provided along a common axis from oneside of the IGU. This arrangement allows the option of including a pivotsystem for swiveling one or more components of the optical system aroundto image and mitigate defects to reach corners or underneath spacers(not shown) at the edges of the IGU. For example, such as pivot systemcan be used to swivel or otherwise rotate the mirror 1234 described withreference to FIGS. 11A and 11B.

Portable Defect Mitigator Subsystems

Certain embodiments of portable defect mitigators disclosed herein mayinclude one or more of the following subsystems: 1) X-Y stage for movingthe optical system with respect to the window surface to increase thefield of view; 2) one or more Z-stages for moving the focal point; 3)tether system; 4) a vacuum engagement system for affixing the portabledefect mitigator to the surface of the window; 5) a dynamic autofocussystem; 6) imaging and mitigation subsystems which share a common axisfrom a dichroic mirror through the focal lens and onto the windowsurface, 7) a pivot system for pivoting the optics in a portable defectmitigator mounted to the window in order to image and mitigate defectsat the corners or underneath a spacer of an IGU; 8) a chassis; 9)case-like structure with a separate chassis; 10) a tracking stylus; and11) a beam blocker.

An example of a portable defect mitigator 1400 with many of theabove-listed subsystems can be found described below with reference toFIGS. 13A-I. Other examples of the above-listed subsystems can be foundthroughout the disclosure. For example, a dynamic autofocus system isdescribed in a section above. As another example, imaging and mitigationsubsystems which share a common axis from a dichroic mirror through thefocal lens and to surface of a window are described above with referenceto FIG. 11A, FIG. 11B, FIG. 12, and FIG. 5C. As another example, a pivotsystem is described below with reference to FIG. 11A and FIG. 11B. Incertain embodiments, the portable defect mitigators described withreference to FIGS. 13A-I and FIG. 14 may include the optical systemdescribed with reference to FIGS. 11A, 11B, and 12.

Chassis

The chassis is of a compact and low weight design for handheld operationby the user. In one example, the chassis structure and its contentsweigh about 10 pounds. Although the chassis structure may be of anyshape, the chassis of certain implementations is in the general shape ofa rectangular box. In some cases, the chassis structure may be made of alow weight material such as, for example, carbon-fiber based compositematerials. In most cases, the chassis is designed as a light-tightenclosure to ensure that laser light does not leave the chassis duringmitigation for safety concerns. The chassis may include one or morehandles to facilitate portability. The handles are designed to allow theoperator to affix the chassis to the window surface. The chassis hascomponents designed to mate and engage the portable defect mitigator tothe surface of the window during operation.

FIG. 13A is an isometric drawing a portable defect mitigator 1400including a box-shaped chassis 1410, according to an embodiment. In theillustrated embodiment, the chassis 1410 is a light tight enclosure. Thechassis 1410 is in a general form of a box having approximate dimensionsof 7.5 inches×7.5 inches on the face for engaging the window and 8inches in width. In other embodiments, the chassis may be of a smallersize. In the illustrated example, the chassis 1410 in the process ofbeing affixed to an IGU 1270 having two electrochromic lites. Thechassis 1410 in the illustration is a carbon-fiber based design and thechassis and its contents weigh about 10 lbs.

The chassis 1410 includes two handles 1420. Each handle 1420 is attachedat two ends to two flanges connected along opposing edges of a surface1430 of the chassis 1410. The chassis 1410 also includes two ports 1440,1442 extending from the back surface 1430. The first port 1440 may be avacuum port for attaching a vacuum line. The other end of the vacuumline may be connected to a vacuum device. The second port 1442 may be apower port for connecting a power line. The power line may be connectedto a power source. The chassis 1410 also includes a protruding portionhaving an input port 1450.

Separate Case

In certain embodiments, a portable defect mitigator will include twomain portions: 1) a first portion with a case-like (e.g.,briefcase-like, suitcase-like, etc.) structure that holds theelectronics, software, and optionally a user interface, and 2) aseparate second portion with a chassis containing components of theoptics system, the dynamic autofocus system, stages for the opticalcomponents, and devices for affixing the chassis to the surface of thewindow. In some implementations, the laser is in the case-likestructure. In other implementations, the laser is in the separatechassis. The chassis portion is separate from the case-like structureand is typically in a compact and light-weight design that can behandheld during operation. The chassis portion is designed to mate andengage to the surface of the window to be remedied. While the case-likeportion may also be handheld, it is designed to contain the heavier andbulkier components of the portable defect mitigator. This allows thechassis portion to be lighter, easily maneuverable by the operator, andcapable of being affixed to the surface of the window during operation.

Components within the chassis may be in communication with componentswithin the case-like structure through one or more connectors. Forexample, there may be a fiber-optic cable between the laser in thecase-like structure and the optics in the separate chassis to propagatelight from the laser through the optics to mitigate the defect at thewindow. As another example, there may be a vacuum line between a vacuumdevice in the case-like structure and the vacuum system in the chassisto apply a vacuum to the vacuum system holding the chassis to the windowduring defect imaging and mitigation. In yet another example, there maybe a power line between a power source in the case-like structure andthe chassis.

Tether

In certain embodiments, the portable defect mitigator may include atether system for added safety. The tether subsystem may include avacuum device (e.g., suction cup) that is connected to a tether line.The tether line is attached to the portable defect mitigator, forexample, at the portion of the chassis facing upward. Some examples ofdevices that can be used as tether lines include a cable, aspring-loaded reel, or a reel counterbalance. The vacuum device may beattached to a structure located above the defect area such as, forexample, a wall above the electrochromic window or a portion of theelectrochromic window itself. The vacuum device can provide an anchorand provides an upward force to the tether line that can take somemoment off the laser head and/or the engagement system (e.g., the vacuumengagement system discussed below) used to affix the portable defectmitigator to the window. In addition, the tether system can provide asafety line that can hold the portable defect mitigator if theengagement system fails or if the mitigator is dropped when moving itfrom one defect area to another defect area on the window.

Vacuum Engagement System

In certain embodiments, the portable defect mitigator includes a vacuumengagement system for affixing the chassis to the surface of the windowduring the defect imaging and mitigation procedure. The vacuumengagement system is designed to make a substantially rigid engagementbetween the window and the portable defect mitigator.

FIG. 13B is an isometric drawing of the portable defect mitigator 1400depicted in FIG. 13A. In this illustration, the portion of the portabledefect mitigator 1410 that engages the window in shown. This portionincludes a vacuum engagement system 1470 with O-rings for affixing theportable defect mitigator 1400 to a surface of a window. The vacuumengagement system 1470 includes a mating base plate 1472 having aplurality of three shallow low-profile recessed regions 1474, 1476, 1478(e.g., recesses) and a circumferential groove around each region. Inother embodiments, the plurality of recesses may have other numbers ofrecesses (e.g., two or more). Each of the low-profile regions 1474,1476, 1478 can from a vacuum seal with the window using O-rings or othersealing member that fit into the circumferential grooves. When mating tothe window surface, each of the low-profile regions 1474, 1476, 1478forms a separate shallow vacuum chamber with the window. Each one of thelow-profile regions 1474, 1476, 1478 is designed (e.g., with a largeenough area and depth) to create a vacuum chamber sufficient (i.e. withenough suction force) to hold the chassis portion onto the surface ofthe window during mitigation. Based on this triple safety design, if anytwo of the vacuum chambers loses vacuum, the remaining vacuum chambercan hold the chassis 1410 engaged with the window. For additionalsafety, each of the vacuum chambers is separately controllable (e.g., bya set of valves) and isolated, so that if any one of the vacuum chambersloses vacuum, the other two chambers do not similarly lose vacuum andcan keep the chassis 1410 engaged with the window. For example, thesystem may have a set of valves. Each valve controls vacuum in a singlechamber associated with that valve. In some cases, the valves may beindependently controlled.

In this illustration, a laser beam 1480 is shown extending from thesurface of the chassis 1410 through an area separate from thelow-profile regions 1474, 1476, 1478. In some cases, the vacuumengagement system 1470 may also include a feedback control system thatdetermines if one or more of the chambers loses vacuum. If one or morevacuum chambers loses vacuum, the feedback control system can send ashutoff signal to the laser, which may provide additional safety.

In certain implementations, the portable defect mitigator may employ aClass 4 laser for defect mitigation. In these cases, there may be apotential risk if the mitigator disengages from the window duringmitigation that the laser beam directed outside the light tightenclosure can potentially cause injury. The triple safety vacuumengagement system 1470 of FIG. 13B and engagement systems of otherdisclosed embodiments can help ensure that the portable defect mitigatordoes not disengage from the window during defect mitigation.

In some cases, a tether system describe herein may also be included toprovide additional safety if the engagement system disengages. In othercases, a low power consumption laser may be used, which allows for anon-tethered defect mitigator. In one of these cases, the low-profileregions 1474, 1476, 1478 cavities may be welded to form a plenum thatcould store vacuum, enabling the use of a very small pump to pump outthe plenum and be valved to and then stuck to the window. Although ahigh velocity vacuum may be need to provide the initial suction to thewindow in a short amount of time, very little vacuum is required tomaintain the vacuum once affixed to the window. Having a storage volumecan enable using a vacuum pump on board and could go along with enablingthe use of a diode or low power consumption laser thus having anon-tethered defect mitigator.

X-Y Stage and Z Stages Position Adjustments

In certain embodiments, the field of view of the optical detector (e.g.,camera) in a portable defect mitigator may be a relatively small area(e.g., an area of about 7 mm×7 mm). To widen the field of view of theoptical detector and also to be able to move the laser over a largerarea, the portable defect mitigator may include an X-Y stage and/or orZ-stage that can move relative to the window onto which the portabledefect mitigator is mounted. The X-Y stage is associated with movementin a plane that is parallel to the surface of the window. The Z-stage isassociated with movement normal to the plane parallel to the surface ofthe window.

The optical system or components (e.g., laser and/or optical detector)of the optical system can be mounted to an X-Y stage to widen the fieldof view of both the optical detector and the laser. By using such X-Ystage, a portable defect mitigator affixed to the window can have a wideimaging and mitigating area. In some embodiments, an X-Y stage may beable to move the optical system over an area of the window surface inthe range of between 7 inches×7 inches. The X-Y stage can be mounted toa Z-stage. The Z-stage can provide movement toward and away from thewindow surface. In some embodiments, a portable defect mitigatorincludes two Z-stages: 1) a first stage for adjusting the optics toroughly locate the focal point at a surface of IGU; and 2) a secondZ-stage for focusing the optics. The first stage may have a wider rangeof movement (e.g., 1 inch, 1.5 inches, 2 inches, etc.) than the secondstage.

FIG. 13C is an isometric drawing of components of the portable defectmitigator 1400 depicted in FIGS. 13A and 13B. In this illustratedexample, the side and back panels of the chassis 1410 have been removedto view the components within. These components include an opticalsystem 1490 mounted to an X-Y stage 1500. The X-Y stage is connected toa first Z-stage 1510. The Z-stage includes X-axis, Y-axis, and Z-axis atthe corner. The Z-stage 1510 has cutouts that slidably connect to threelinear screws 1535 affixed at one end to the base plate 1472 of thechassis 1410. This connection allows the stage mounting plate 1510 tomove in the Z direction with respect to the base plate 1472 and thewindow, which will be described in more detail below in reference toFIGS. 13D and 13E. The X-Y stage 1500 can move in the X-direction andY-direction relative to the first Z-stage 1510 and the first Z-stage1510 can move in the Z-direction relative to the base plate 1472. Thepotable defect mitigator 1400 also includes a second Z-stage that is acomponent of a dynamic autofocus system. In the illustrated example, theX-direction refers to both the positive and negative direction in anaxis parallel to the X-axis, the Y-direction refers to both the positiveand negative direction in an axis parallel to the Y-axis, and theZ-direction refers to both the positive and negative direction in anaxis parallel to the Z-axis.

FIGS. 13D and 13E are isometric drawings of components of the portabledefect mitigator 1400 depicted in FIGS. 13A-C. In FIGS. 13D and 13E, thechassis 1410 and the optical system 1490 have been removed to view theX-Y stage 1500 and other components of the portable defect mitigator1400. The portable defect mitigator includes a mechanism (e.g., a highspeed motor) that controls the movement of the X-Y stage 1500 and themounted optical system 1490 in the X-direction and in the Y-directionrelative to the surface of the window.

The X-Y stage 1500 includes two sliding platforms 1501(a) and 1501(b).Sliding platform 1501(a) can slide in the X-direction within a set ofrails. Sliding platform 1501(b) slides in the Y-direction within a setof rails. The X-Y stage 1500 includes two mechanisms for rotatingthreaded rods. The first mechanism rotates a first threaded rod toengage and translate sliding platform 1501(a) in the X-direction. Thesecond mechanism rotates a second threaded rod to engage and translatesliding platform 1501(b) in the Y-direction. The first and secondmechanisms controlling the threaded rods can be manually controlled bythe operator or automatically controlled by an actuator that receivescontrol signals from a processor of the portable defect mitigator 1400.For example, these mechanisms can be a linear motor, manual linearactuator, etc. In the illustrated embodiment, the field of vision of theoptical detector in the optical system 1490 is about 7 mm×7 mm at thesurface of the electrochromic device. By employing the X-Y stage 1500,the field of vision of the optical detector and laser is increased to 22mm×22 mm.

The portable defect mitigator 1400 also includes a thickness adjustmentknob 1530, a glass thickness indicator 1532, a belt and gear assembly1534, and three linear screws 1535, and two posts 1537 (shown in FIG.13E). These components are used to adjust the Z-direction coordinate ofthe optical system 1490 to calibrate the optical system 1490 accordingto the thickness of the window being mitigated. In one case, theZ-direction coordinate can be adjusted to locate the focal point of thelaser at a surface of the electrochromic device of an electrochromicwindow in an IGU before the window flexes. The Z-direction coordinate isadjusted by rotating the thickness adjustment knob 1530. In one case,the thickness adjustment knob 1530 may be rotated to align a marker onthe thickness adjustment knob 1530 to an appropriate indicator on theglass thickness indicator 1532. The glass thickness indicator 1532 mayhave a series of indicators that designate different thicknesses.

This adjustment may be based on one or more window parameters such as,for example, the thickness of the insulated glass unit, the thickness ofthe window unit, the thickness of the spacer, the thickness of each paneor lite, etc. In one embodiment, the adjustment may be based on thestandard thickness of the window (or IGU) and/or the thickness betweenthe surface of the engaged lite to the surface of the electrochromicdevice having the defect. The adjustment can be used to calibrate thestarting position of the focal point of the laser. For example, if thedefect is located on an electrochromic device of an outer lite(non-engaged lite) of an IGU having multiple lites, the thicknessadjustment knob 1530 can be used to calibrate the starting position ofthe focal point of the laser at a surface of the electrochromic deviceof the outer lite. If the defect is located on an electrochromic deviceof the engaged lite, the thickness adjustment knob 1530 can be used tocalibrate the starting position of the focal point at the electrochromicdevice of the outer lite. This adjustment is generally made beforeinitiating the defect imaging and mitigation process. Once this processstarts, a dynamic autofocus system 1000 shown with respect to FIG. 9 canbe used to make fine adjustments to the Z-position of the focal point toaccommodate for flexing or other movement of the window. In some cases,an LED or other type of indicator can be used in concert with thedynamic autofocus system or other means of measuring glass thicknessdescribed herein to precisely adjust the Z-position either manually orautomatically where the linear screws 1535 can be turned by electricmotors.

The belt and gear assembly 1534 includes a series of gears engaged tomove by at least one belt. One of the gears is a master gear affixed toan end of a linear screw 1535 having the glass thickness adjustment knob1530 at the opposing end. Rotating the glass thickness adjustment knob1530 rotates the master gear at the end of the linear screw 1535, whichmoves the belt, which rotates the other gears including slave gearsattached to the other linear screws 1535. Thus, rotating the glassthickness adjustment knob 1530 effects equivalent and simultaneousrotation of all three linear screws 1535. The linear screws 1535 includea threaded portion at the end proximal the mounting plate 1510. Thethreaded portion of the linear screws 1535 movably engages a linearscrew nut 1536 affixed to the mounting plate 1510. As the linear screws1535 are rotated using the glass thickness adjustment knob 1530, themounting plate 1510 translates in the Z-direction guided by the twoposts 1537 with linear bearings to adjust the Z-position of the mountingplate 1510. The portable defect mitigator 1400 also includes a guideshaft 1537 between the base plate 1472 and the stage mounting plate1510. The portable defect mitigator 1400 also includes an optional belttensioner 1538. The belt tensioner 1538 allows an idle gear to be movedon a slide to tighten the belt.

In one embodiment, the portable defect mitigator 1400 may include asystem where the linear screws 1535 can be turned by electric motors.For example, a triangulation sensor may provide feedback to indicatewhen to stop moving the linear screws 1535.

The portable defect mitigator 1400 depicted in FIGS. 13A-E also includesan optical system 1490 with a similar arrangement to that of the opticalsystem 1200 depicted in FIG. 11. FIGS. 13F, 13G, 1311 are isometricdrawings of components of optical system 1490. Optical system 1490includes a laser input 1491 and a laser optics block 1492 incommunication with laser input 1491. Laser input 1491 includes port 1450connected to optical fiber 1460. Laser optics block 1492 is incommunication with a main optics block 1493. The optical system 1490also includes an optical detector 1494 (e.g., camera), a vision opticsblock 1495, and a dynamic autofocus system having a triangulation sensor1132. The autofocus system is similar to the dynamic autofocus system1000 describe with reference to FIG. 9 and includes triangulation sensor1132.

In the optical system 1490, there is a coaxial optical path between thelaser input 1491 and the detection optics 1494 to align the detectionand mitigation processes. In addition, collimated light is provided fromthe laser and optical detector along the coaxial path to the focusinglens. This arrangement allows the dynamic autofocus system to adjust thefocusing lens to dynamically focus both the laser and optical detectorto the same focal point 1480 as the window may flex during the imagingand mitigation process.

-   -   Pivot System

In some cases, defects can be concentrated near the edges of anelectrochromic window in an IGU. This can sometimes be the result ofscribing processes performed on a fabricated window. While the spacer atthe edges of the IGU may partially obscure these edge defects, thepenumbra or halo around the defects may well extend into the viewablearea inside the footprint between the spacers.

Embodiments disclosed herein include a portable defect mitigator thatcan mitigate defects underneath the spacer and at the corners. Theseportable defect mitigators may be particularly effective in mitigatingdefects in a cantilevered spacer design, which allows greater access bydefect mitigation optics to reach underneath the spacer. An example of acantilevered spacer design and other spacer designs can be found inPatent Application Ser. No. 61/421,154, filed on Dec. 28, 2010, entitled“Improved Separators for Insulated Glass Units,” which is herebyincorporated by reference in its entirety.

The optical systems shown in FIGS. 11A-11B, in FIG. 12, and in FIGS.13A-H, and in other disclosed embodiments are particularly adaptable topivot the focal point of the laser to mitigate under the spacer and atthe corner. In these systems, the propagated light from the laser 1220and optical detector 1210 are provided along a common axis path from oneside of the IGU. This arrangement allows the option of including a pivotsystem for pivoting the final optics path of the laser and visiontogether to image and mitigate defects to reach corners or underneathspacers at the edges of an IGU. Basically, the pivot system allows forpivoting around the laser dot on the dichroic mirror surface in anydirection. In one embodiment, a pivot system includes a pivot mechanism(e.g., motor) that can control the rotation of the mirror 1234 and thefirst lens 1230 described with respect to FIGS. 11A and 11B. Anotherexample of a pivot system includes a mechanism for pivoting the dichroicmirror (e.g., dichroic mirror 1240) and the focal lens (e.g., lens 1230)as a unit along an axis in a plane parallel to a plane approximating thesurface of the electrochromic device. For example, the pivot systemcould pivot the X-Y stage 1500 about one or more axes lying in the X-Yplane, which is parallel to the plane approximating the surface of thewindow.

In embodiments having a pivot system, the laser beam is pivoted at anangle, which could reflect off a back plate and out of the light tightenclosure of the chassis. In these embodiments, the portable mitigatormay include a light blocking material (e.g., hat, sleeve, etc.) placedskirting out from the side of the chassis to extend the light tight areaand provide side protection from the laser beam.

Tracking Stylus

In certain embodiments, a portable defect mitigator will include atracking stylus to set the coordinates of the focal point for mitigatingthe defect. For example, a user can place the tracking stylus at or nearone or more defects of an electrochromic window in a tinted state todefine the coordinates of the one or more defects. The defect(s)coordinates can be communicated to a processor which determines a set ofinstructions for automatically mitigating the one or more defects. Theseinstructions may include information for operating the laser and formoving the laser to the coordinates. These instructions may becommunicated to the motor controlling the X-Y stage, the pivot system,and/or other system for locating the focal point of the laser at thecoordinates of the defects. The set of instructions is also communicatedto the laser to control the timing and energy of the emissions from thelaser.

Beam Blocker

In certain embodiments, a portable defect mitigator may include a beamblocker. The beam blocker is affixed to an outer surface of the IGUadjacent the defect being mitigated. The outer surface is opposite thesurface of the IGU to which the portable defect mitigator is attached.The beam blocker reflects or blocks the laser light from exiting throughthe outer surface to address safety concerns. The beam blocker may alsobe used as a detection mechanism 1030 to measure the distance to thesurfaces within the IGU. In this case, other detection methods may beemployed such as ultrasonic, capacitive, or other laser measurementtechniques. Using a beam blocker may be a less expensive alternative tousing an internal triangulation sensor.

Exemplary Method of Defect Imaging and Mitigation

FIG. 14 is a flowchart of a method of defect imaging and mitigation,according to embodiments. At step 1715, a window is identified fordefect remediation. In some cases, this may involve a human detecting ahalo or other perceptible defect in a window in the tinted state. Thehuman may visually inspect or use a magnification device (e.g.,microscope) to determine whether there is a defect. In other cases, thedefect may be determined by an automated detection system that uses alight detector to measure light transmitted through the window in thetinted state to identify the window for remediation. In yet other cases,the defect may be determined using thermal imaging such as, for example,lock-in thermography.

At step 1720, a portable defect mitigator is mounted to the surface ofthe window near the region where the defect was observed. For example,the chassis portion 1410 of the portable defect mitigator 1440 can beaffixed as shown in FIG. 13A to a surface of an electrochromic window.The portable defect mitigator can be mounted to the surface usingvarious attachment methods. For example, the portable defect mitigatormay be mounted to the surface using a vacuum engagement system such as,for example, triple safety vacuum engagement system 1470 described inreference to FIG. 13B that forms three isolated vacuum chambers with thesurface, each capable of holding the chassis 1410 to the window. Asanother example, the portable defect mitigator may be mounted to thesurface using a mechanical clamp.

At step 1725, the imaging system of the portable defect mitigator isbrought into focus with the surface of the electrochromic device. Asharp image of the surface is generated at the optical detector (e.g.,camera) when the focal lens and the surface of the electrochromic deviceare separated by the focal length of the lens. Moving the lens to theproper separation can be accomplished either manually or automatically.In one example, the portable defect mitigator may have an autofocusdevice that can move the lens to the proper focal length. In anotherexample, the operator may move the lens manually to focus on thesurface. In yet another example, an operator using a portable defectmitigator 1400 depicted in FIGS. 13A-H may rotate a thickness adjustmentknob 1530 to move the focal point of the laser near or at the surface ofthe electrochromic device based on a standard thickness of theelectrochromic window or IGU. In some cases, this is an approximationand only roughly places the focal point at the surface. This is usedwhen remedying defects in an IGU. The rough approximation is a startingpoint to ensure that the focal point is at the correct surface of anIGU. The operator or automated system can finely tune the focus to theplane at the surface once the focal point is close to the surface. Thishelps to ensure that the defect mitigator is focused on the correctelectrochromic device where there may be more than a singleelectrochromic device, for example, in an IGU.

At step 1730, the optical system of the portable defect mitigatoroptionally targets the defect area within the field of view of the imageand mitigation system. In some cases, the optical system may be moved inthe x-direction and the y-direction to center or otherwise locate fieldof view of the optical detector and laser proximal the defect. Forexample, the portable defect mitigator 1400 depicted in FIGS. 13A-Hincludes an X-Y stage for moving the optical system in the X-directionand the Y-direction. The X-Y stage can be moved so that the defect is ator near the center of the field of view. In some embodiments, step 1730is performed prior to step 1725.

Once the image system is properly focused on a field of view of theelectrochromic device surface, the putative defects within the field ofview are identified (step 1735). A processor (e.g., microprocessor) inthe portable defect mitigator may process code or other logic havinginstructions to identify the putative defects within the field of viewbased on the intensity of light detected as passing through particularregions in the field of view. The logic may also include instructions toidentify the putative defects by location and intensity or othercharacterizing parameters (e.g., wavelength, etc.) of the light. Theprocessor may also process code having instructions that define a scribecircle or other scribe pattern around the putative defect.Alternatively, the user can specify a scribe circle or other scribepattern using a user interface. Some examples of variations on a simplecircular scribe pattern can be found in U.S. Patent Ser. No. 61/649,184,filed on May 18, 2012, entitled “CIRCUMSCRIBING DEFECTS IN OPTICALDEVICES,” which is hereby incorporated by reference in its entirety. Inone implementation, the user can select any one or more of theseputative defects to be mitigated using a user interface. When the userselects such defects, the X-Y stage may align the system to the defectsby putting them in the center of the field of vision. At that location,the scribe laser is also aligned with the defect.

Once the defect for mitigation and the associated scribe diameter havebeen determined, the portable defect mitigator can execute the laserscribe to mitigate the defect. At step 1740, the portable defectmitigator mitigates the selected defect based on the selected scribediameter. In some cases, an X-Y stage may be used to translate the focalpoint along the scribe pattern within the scribe diameter. In somecases, a dynamic autofocus system can be used to adjust the z-positionof the focal point during scribe. For example, the dynamic autofocussystem 1000 depicted in FIG. 11 can be used to determine any movement ofthe surface of the electrochromic device during mitigation. If thedynamic autofocus system 1000 determines that the surface has moved,typically due to window flexing, the system 1000 can adjust the lens toplace the focal point back at the surface.

After the scribe has taken place, a confirmatory image may be capturedto ensure that the defect has been appropriately mitigated, at step1745. In this regard, the gradient of light intensity can be measured inthe X or Y direction. A very steep gradient suggests that theremediation was effective. An un-remedied halo defect has a very gradualor diffuse variation in light intensity. After the remediation iscompleted at a particular location on the window, the defect mitigatormay be disengaged by breaking vacuum and either put away or move to adifferent portion of the window, or even a different window in thevicinity, and used to remedy one or more additional defects.

In one embodiment, a pivot system is employed. The pivot system isdesigned to allow the detection and/or scribe optics to pivot such thatthe scribe laser can strike the surface of the electrochromic device atan angle deviating from the normal (i.e., an angle other than 90° fromthe plane of the device). Thus, the pivot system can be used to allowthe optical system to be able to view and/or mitigate a defect under aspacer or a corner of an IGU.

The portable defect mitigator does not move as a whole during a typicaldefect identification and mitigation procedure. However, there may bevibration or another external force on the structure with the defectbeing mitigated that moves the structure with the portable defectmitigator attached during an identification and mitigation procedure.For example, there may be vibration from the wall or other buildingcomponent to which the rail system in FIG. 5A is attached. In certainembodiments, active and/or passive vibration isolation can be used toisolate the portable defect mitigator from these forces. For example,components having materials and geometry tuned to dampen the predictedor measured vibrations can be used to passively isolate the portabledefect mitigator from the vibrations. In an example using activestabilization, a gyroscope or pendulum may be used to actively stabilizethe portable defect mitigator from the vibrations.

In one embodiment, the portable defect mitigator may include an opticalsystem having a laser mitigating the defect, an optical detector (e.g.,camera), and an illumination device that do not have the same co-axialoptical path. In this embodiment, other mechanisms can be used to pairthe focus of the laser, illumination device, and optical detector. Byseparating the optical path of one or more of these devices, the opticsin these devices can be individualized optimized. In addition, byseparating the optical path, there can be automated and independentmovement of each device for focusing purposes. This can enable theindividual design of different focusing characteristics, such as focaldepth and area of focus, for each of the devices.

In one embodiment, a dynamic autofocus system may determine thedistances to the deformed surfaces of an IGU. Based on these distances,the dynamic autofocus system may be able to determine the opticalproperties of the deformed surfaces of the IGU. The dynamic autofocussystem may accommodate for these changes by adjusting the laserparameters used for mitigation. For example, the dynamic autofocussystem may adjust the focal distance needed for the laser based on theoptical properties of the deformed IGU surfaces.

One of ordinary skill in the art will appreciate that variouscombinations of the above embodiments are contemplated in thisdescription. For example, apparatus 400 and/or 500 may include wirelesscommunication components. In another example, apparatus 600 may travelon a rail system such as described in relation to FIG. 5B, even thoughapparatus 600 is smaller than the window pane upon which remediation isintended. In another example, apparatus 500 may be on a cart or tablerather than a tripod. In yet another example, the identificationmechanism and the mitigation mechanism may be apart from one another,not adjoining as depicted in the figures. In another example, theidentification mechanism and the mitigation mechanism may haveindependent movement mechanisms. In yet another example, base 605 ofapparatus 600 (see FIG. 7) may have a mechanism for rotating theidentification mechanism and/or the mitigation mechanism. In yet anotherexample, X-Y stages may have various configurations, methods of drivinglinear or rotation actuators and the like.

Although the foregoing has been described in some detail to facilitateunderstanding, the described embodiments are to be consideredillustrative and not limiting. It will be apparent to one of ordinaryskill in the art that certain changes and modifications can be practicedwithin the scope of the appended claims.

What is claimed is:
 1. A dynamic autofocus system for automaticallyfocusing a laser during mitigation of a defect in an electronic devicedisposed on a deforming window that is deforming during defectmitigation, the dynamic autofocus system comprising: a focal lensconfigured to focus collimated light from the laser mitigating thedefect; a detector mechanism configured to take measurements over timeof separation distance to a surface of the electronic device disposed onthe deforming window; a processor configured to: calculate a rate ofchange of separation distance using the measurements taken over time bythe detector mechanism; predict a first prediction distance occurring ata future time using the rate of change calculated; and send a signal toa lens positioning mechanism to move the focal lens; and the lenspositioning mechanism configured to move the focal lens to about a focallength from the surface of the electronic device using the firstprediction distance predicted to occur at the future time.
 2. Thedynamic autofocus system of claim 1, wherein the processor is part ofthe detector mechanism.
 3. The dynamic autofocus system of claim 1,wherein the focal lens is further configured to pass coaxial light fromthe laser and from an illumination device to an optical detector.
 4. Thedynamic autofocus system of claim 1, wherein the lens positioningmechanism is configured to move the focal lens to automatically focusthe laser at the defect as the deforming window is deforming duringdefect mitigation.
 5. The dynamic autofocus system of claim 1, whereinthe processor is further configured to: (i) determine whether to movethe focal lens based on whether at least one of the measurements ofseparation distance is determined to have a value outside apredetermined range, and (ii) send the signal to the lens positioningmechanism based on the determination.
 6. The dynamic autofocus system ofclaim 1, wherein the detector mechanism is a triangulation sensor. 7.The dynamic autofocus system of claim 1, wherein the electronic deviceis an electrochromic device.
 8. A method for dynamic autofocusing alaser to mitigate a defect in an electronic device disposed on adeforming window, the method comprising: reflecting, using a mirror,coaxial light from an illumination device and the laser to a focal lens:rotating the mirror and the focal lens together about a pivot point todirect the focused light at different angles; measuring a separationdistance to a surface of the electronic device; focusing the laser byautomatically moving the focal lens to about a focal length from thesurface of the electronic device using the separation distance measured;and mitigating the defect using the focused laser.
 9. The method fordynamic autofocusing of claim 8, further comprising determining whetherto move the focal lens based on the separation distance measured havinga value outside a predetermined range.
 10. The method for dynamicautofocusing of claim 8, wherein the electronic device is anelectrochromic device.
 11. A method for dynamic autofocusing a laser tomitigate a defect in an electronic device disposed on a deformingwindow, the method comprising: reflecting, using a mirror, coaxial lightfrom an illumination device and the laser to a focal lens; passing, bythe focal lens, coaxial light scattered by a surface of the electronicdevice to an optical detector; detecting a location of the defect basedon light received at the optical detector; automatically rotating themirror and the focal lens together about a pivot point to locate thefocal point of the laser and the illumination device at the surface ofthe electronic device before mitigation; measuring a separation distanceto the surface of the electronic device; focusing the laser byautomatically moving the focal lens to about a focal length from thesurface of the electronic device based on the separation distancemeasured; and mitigating the defect using the focused laser.
 12. Themethod for dynamic autofocusing of claim 11, the method comprisingdetecting intensity of light passing through the defect in the deformingwindow while the deforming window is in a darkened tint state todetermine the location of the defect.
 13. A dynamic autofocus system forfocusing a laser during mitigation of a defect in an electronic devicedisposed on a deforming window, the dynamic autofocus system comprising:a mirror reflecting coaxial light from an illumination device and thelaser to a focal lens, wherein the mirror and the focal lens areconfigured to rotate together about a pivot point to direct the focusedlight at different angles; the focal lens configured to pass coaxiallight from the laser mitigating the defect and from the illuminationdevice; a detector mechanism configured to measure a distance to asurface of the electronic device; and a lens positioning mechanismconfigured to automatically move the focal lens during mitigation toabout a focal length from the surface of the electronic device of thedeforming window, wherein the lens position mechanism is configured toautomatically move the focal lens based on the distance measured to thesurface of the electronic device.
 14. The dynamic autofocus system ofclaim 13, wherein the lens positioning mechanism is further configuredto determine whether to move the focal lens based on the distancemeasured having a value outside a predetermined range.
 15. A dynamicautofocus system for focusing a laser during mitigation of a defect inan electronic device disposed on a deforming window, the dynamicautofocus system, the dynamic auto focus system comprising: a mirrorreflecting coaxial light from an illumination device and the laser to afocal lens, wherein the mirror and the focal lens are configured toautomatically rotate together about a pivot point to direct the focusedlight to a detected location of the defect on the deforming window; anoptical detector configured to detect a location of the defect usingillumination from the illumination device scattered from a surface ofthe electronic device, wherein the focal lens is configured to passcoaxial light scattered from the surface of the electronic device to theoptical detector; a detector mechanism configured to measure a distanceto the surface of the electronic device; and a lens positioningmechanism configured to automatically move the focal lens duringmitigation to about a focal length from the surface of the electronicdevice of the deforming window, wherein the lens positioning mechanismis configured to automatically move the focal lens based on the distancemeasured to the surface of the electronic device.